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Focusing on David B. Riazanov career and his pioneering efforts in producing a complete edition of the works of Marx and Engels, the article explains why Riazanov’s variety of Marxism was unacceptable to the Soviet regime, and why from 1924 Lenin was credited with being an outstanding Marxist theoretician, whereas previously he had been regarded only as a skilled political activist. The concept of Leninism as a new stage of Marxism was put forward by Bukharin and elaborated on by Stalin and Zinoviev. Georg Lukács attempted to show that Lenin’s thought had the internal coherence that Bukharin postulated. In support of Lenin’s theoretical credentials, his ‘Philosophical Notebooks’ began to be published from 1925. However, neither Riazanov nor his associate Abram M. Deborin subscribed to the official doctrine that Leninism was a new and higher stage of Marxism. For this stance they fell victim to Stalin’s repression.

(–)–Zampanolide is a marine microtubule-stabilizing macrolide that has been shown by in vitro experiments to be a promising anticancer lead compound. Through its unique covalent-binding with β-tubulin, zampanolide exhibits cytotoxic potency towards multi-drug resistant cancer cells that is superior to paclitaxel. However, the limited availability of zampanolide impedes its further in vivo evaluation as a viable drug candidate. Zampanolide is envisioned to become more drug-like if its chemically fragile side chain can be stabilized; hence, this project aims to develop mimics of zampanolide with a stable side chain using straightforward synthetic methods. To this end, twelve novel zampanolide mimics (51-62) with conjugated and planar side chains have been synthesized via a 24-step sequence for each mimic from commercially available 2-butyn-1-ol as starting material. A Horner-Wadsworth-Emmons reaction incorporates the α,β-unsaturated ketone side chain and also closes the core macrocycle. WST-1 cell proliferation assays in three docetaxel-sensitive and two docetaxel-resistant human prostate cancer cell models confirm that a suitably designed side chain can serve as a bioisostere for the N-acyl hemiaminal side chain in zampanolide. Mimic 52 with a 17R chiral center was identified as the optimal candidate with IC(50) values of 0.29–0.46 μM against both docetaxel-sensitive (PC-3 and DU145) and docetaxel-resistant prostate cancer cell lines (PC-3/DTX and DU145/DTX). Zampanolide mimic 52 exhibited equivalent antiproliferative potency towards both docetaxel-sensitive and docetaxel-resistant cell lines, with relative resistance in the range of 0.9–1.6.

Alexander Bogdanov’s Empiriomonism is not a single work but a series of essays originally published in three volumes between 1904 and 1906. The opening essays of the first volume were written while...

While working on the final draft of Das Kapital Volume I, Marx discovered that the assumption that he had previously held: as it circulated capital extended its sphere of operation and at the same time absorbed earlier forms of economic organization was not supported by empirical evidence. From 1869 he began to study how in fact capital began to circulate in Russia, a country which had begun to create a capitalist economy after the liberation of the peasantry in 1861. Marx was aided in this project by Nikolai Danielson, who sent him materials on the Russian economy and who himself made a study of contemporary trends in Russian economic development. Marx contributed to the article Danielson published in 1880 on this subject. One of the works Marx acquired was the book by Vorontsov, who concurred with Danielson that only some features of capitalism were present in the Russian economy and that peasants were dispossessed without being re-deployed in capitalist enterprises. Marx died without incorporating his Russian material into the second volume of Das Kapital. Engels failed to see any problem with the circulation of capital and published the manuscripts as he found them, dispersing Marx’s Russian materials. Unlike Danielson, Engels was convinced that Russia’s economic development did not differ in any way from that of Western Europe, a conviction shared by Plekhanov and Lenin, who classed Danielson and Vorontsov as “narodniki.” Lenin’s book The Development of Capitalism in Russia is a polemic against Danielson and Vorontsov, but does not directly address the points they made.

Chiral salen–metal complexes are among the most versatile asymmetric catalysts and have found utility in fields ranging from materials chemistry to organic synthesis. These complexes are capable of inducing chirality in products formed from a wide variety of chemical processes, often with close to perfect stereoinduction. Salen ligands are tunable for steric as well as electronic properties, and their ability to coordinate a large number of metals gives the derived chiral salen–metal complex very broad utility in asymmetric catalysis. This review primarily summarizes developments in chiral salen–metal catalysis over the last two decades with particular emphasis on those applications of importance in asymmetric synthesis.

Neurological conditions not only can be devastating to patients and families but also are among the most difficult disorders for researchers to understand. More than 1 billion people worldwide currently suffer from some form of neurological disease, the vast majority of which have no effective treatment. The study of neurological conditions in animal disease models is expensive, labor-intensive, and often unsuccessful in recapitulating many aspects of human neurological disorders; treatments based on these models have led to disappointing clinical outcomes despite promising preclinical studies. At the same time, in vitro models using transformed/immortalized human cell lines also face issues of translatability. In the absence of human in vivo models, we believe that the best systems with which to study human neurological conditions and eventually to screen therapeutic agents are those composed of human-patient-derived neural tissue. Induced pluripotent stem cells (iPSC) can be used to generate human disease models by recapitulating disease pathologies in the dish without species barriers or the need for cell immortalization. Additionally, iPSC-derived neural models can be adapted to high-throughput screening platforms, making these systems attractive for industrial-level drug discovery. Patient stratification using iPSC technology can also help to design better clinical trials, and this, in the long run, allows us to deliver the right drugs to the right patients in a shorter period of time. In the current chapter, we discuss the benefits of using patient-derived neurological disease models and the progress that has been made in the last decade in modeling neurological diseases in two-dimensional (2D) and three-dimensional (3D) culture using iPSC technologies. in vitro models useful for the study of neuronal injury and the prediction of molecule-induced neural toxicity are also described.

Known as ’the Father of Russian Marxism’, Plekhanov was the chief popularizer and interpreter of Marxism in Russia in the 1880s. His interest in the philosophical aspects of Marxism made him influential outside as well as inside Russia. He was a prolific writer, and dealt with several aspects of Marxist thought. Plekhanov was an important figure in the Russian revolutionary movement. He was a founder member of the Russian Social Democratic Party, and a leading figure in its Menshevik wing after it split into Bolsheviks and Mensheviks in 1903. As a politician, Plekhanov was constantly involved in polemics with political and ideological opponents. Most of his theoretical works are to some degree polemical, and it was the conflicts among Russian revolutionary groups that shaped Plekhanov’s interpretation of Marx’s thought. A basic feature of this interpretation was that Russia’s historical development was like that of Western European countries, and would pass through a capitalist phase before progressing to socialism. Accordingly, Plekhanov gave prominence to those of Marx’s writings which could be presented in a deterministic way. Plekhanov insisted that Marxism was a materialist doctrine (as opposed to an idealist one) and as such recognized the primacy of matter in all spheres of existence. Plekhanov was in many ways an innovator, being the writer who first coined the term ’dialectical materialism’, and who drew attention to the Hegelian origins of Marx’s system. His writings were quickly translated into several European languages. His interpretation of Marxism was much admired by Lenin, and was to form the basis of the official ideology of the Soviet Union. The conception of Marxism that Plekhanov propounded continues to exercise a profound influence on conceptions of Marxism throughout the world.

Dactylolide and certain analogues are attractive targets for study due to their structural resemblance to zampanolide, a very promising anticancer lead compound and a unique covalent-binding microtubule stabilizing agent. The primary goal of this project is identification and synthesis of simplified analogues of dactylolide that would be easier to prepare and could be investigated for antiproliferative activity in comparison with zampanolide. Extension of Almann's concept of a simplified zampanolide analogue to dactylolide in the form of desTHPdactylolide was attractive not only for reasons of synthetic simplification but also for the prospect that analogues of dactylolide could be prepared in both (17S) and (17R) configurations. Since Altmann's overall yield for the six-step procedure leading to the C9-C18 fragment of desTHPdactylolide was only 8.7%, a study focused on optimized synthesis and antiproliferative evaluation of each enantiomer of desTHPdactylolide was initiated using Altmann's route as a framework. To this end, two optimized approaches to this fragment C9-C18 were successfully developed by us using allyl iodide or allyl tosylate as the starting material for a critical Williamson ether synthesis. Both (17S) and (17R) desTHPdactylolides were readily synthesized in our laboratory using optimized methods in yields of 37-43%. Antiproliferative activity of the pair of enantiomeric desTHPdactylolides, together with their analogues, was evaluated in three docetaxel-sensitive and two docetaxel-resistant prostate cancer cell models using a WST-1 cell proliferation assay. Surprisingly, (17R) desTHPdactylolide was identified as the eutomer in the prostate cancer cell models. It was found that (17S) and (17R) desTHPdactylolide exhibit equivalent antiproliferative potency towards both docetaxel-sensitive (PC-3 and DU145) and docetaxel-resistant prostate cancer cell lines (PC-3/DTX and DU145/DTX).

Bioelectrical regulation of bone fracture healing is important for many cellular events such as proliferation, migration, and differentiation. The aim of this study was to investigate the osteogenic differentiation potential of human mesenchymal stem cells (hMSCs) cultivated on silk scaffolds in response to different modes of electrostimulation (e.g., exogeneous and/or endogeneous). Endogeneous electrophysiology was altered through the use of monensin (10 nM) and glibenclamide (10 μM), along with external electrostimulation (60 kHz; 100-500 mV). Monensin enhanced the expression of early osteogenic markers such as alkaline phosphatase (ALP) and runt-related transcription factor 2 (RUNX-2). When exogeneous electrostimulation was combined with glibenclamide, more mature osteogenic marker upregulation based on bone sialoprotein expression (BSP) and mineralization was found. These results suggest the potential to exploit both exogeneous and endogeneous biophysical control of cell functions towards tissue-specific goals.

Corneal tissue displays the highest peripheral nerve density in the human body. Engineering of biomaterials to promote interactions between neurons and corneal tissue could provide tissue models for nerve/cornea development, platforms for drug screening, as well as innovative opportunities to regenerate cornea tissue. The focus of this study was to develop a coculture system for differentiated human corneal stromal stem cells (dhCSSCs) and dorsal root ganglion neurons (DRG) to mimic the human cornea tissue interactions. Axon extension, connectivity, and neuron cell viability were studied. DRG neurons developed longer axons when cocultured with dhCSSCs in comparison to neuron cultures alone. To assess the mechanism involved in the coculture response, nerve growth factors (NGF) secreted by dhCSSCs including NGF, brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), and neurotrophin-3 were characterized with greater focus on BDNF secretion. DhCSSCs also secreted collagen type I, an extracellular matrix molecule favorable for neuronal outgrowth. This coculture system provides a slowly degrading silk matrix to study neuronal responses in concert with hCSSCs related to innervation of corneal tissue with utility toward human corneal nerve regeneration and associated diseases.

Asymmetric anti-aldol coupling of a norephedrine-derived ester with an α-chiral aldehyde was used to synthesize a carboxylic acid representing the C13-C19 segment of the macrocyclic domain present in the immunosuppressive agent sanglifehrin A. Felkin addition set configuration at the C14-C17 stereotetrad in this unit in which hydroxyl functions at C15 and C17 were masked as an internal ketal. The carboxyl group of this segment was coupled to the N-terminus of the tripeptide portion (C1-N12) of sanglifehrin A macrolactone to assemble the C1-C19 domain. Synthesis of the C20-C25 subunit of sanglifehrin A containing a (23S) alcohol was completed via asymmetric allylation of (E)-3-iodo-2-methylprop-2-enal followed by oxidative cleavage of the terminal vinyl appendage and a Takai olefination with pinacol dichloromethylboronate. Esterification of this alcohol with a C1-C19 carboxylic acid furnished an open C1-C25 macrolactone precursor, but this substance failed to undergo macrocyclization via intramolecular Suzuki-Miyaura coupling.

The article follows the development of Lenin's philosophical conceptions and the historical context in which they emerged. It examines how Plekhanov's interpretation of Marxist philosophy was assimilated by Lenin. In the dispute between Plekhanov and Alexander Bogdanov Lenin took Plekhanov's side and in defence of Plekhanov wrote Materialism and Empiriocriticism. A major influence on Lenin was the correspondence between Marx and Engels published in 1913, which prompted him to study Hegel and other writers mentioned in the correspondence. Although Lenin's commentaries on Hegel and other philosophers were published as ‘Philosophical Notebooks’, the notes Lenin made on the Marx–Engels correspondence were not, owing to Stalin's peculiar requirements of the Lenin cult.

Nerve conduits are a proven strategy for guiding axon regrowth following injury. This study compares degradable silk-trehalose films containing chondroitinase ABC (ChABC) and/or glial cell line-derived neurotrophic factor (GDNF) loaded within a silk fibroin-based nerve conduit in a rat sciatic nerve defect model. Four groups of silk conduits were prepared, with the following silk-trehalose films inserted into the conduit: (a) empty; (b) 1 µg GDNF; (3) 2 U ChABC; and (4) 1 µg GDNF/2 U ChABC. Drug release studies demonstrated 20% recovery of GDNF and ChABC at 6 weeks and 24 h, respectively. Six conduits of each type were implanted into 15 mm sciatic nerve defects in Lewis rats; conduits were explanted for histological analysis at 6 weeks. Tissues stained with Schwann cell S-100 antibody demonstrated an increased density of cells in both GDNF- and ChABC-treated groups compared to empty control conduits (p

A chiral iron(III)-salen complex based on a cis-2,5-diaminobicyclo[2.2.2]octane scaffold catalyzes asymmetric Conia-ene-type cyclization of α-functionalized ketones containing an unactivated terminal alkyne and produces an exo-methylenecycloalkane possessing a stereodefined quaternary center.

A new C2 symmetric cobalt(II)-salen catalyst based on cis-2,5-diaminobicyclo[2.2.2]octane as the chiral scaffold was prepared which, in the presence of potassium thioacetate as the promoter, catalyzed the formation of cyclopropanes from 1,1-disubstituted ethylenes and ethyl diazoacetate in high yield and with excellent diastereo- and enantioselectivity. Asymmetric cyclopropanation with the catalyst was used in a short, efficient synthesis of the dual serotonin-epinephrine reuptake inhibitor (+)-synosutine.

The "northern" sector of the cembranoid diterpene providencin containing a tetrasubstituted cyclobutane was synthesized from the bis(acetonide) of d-glucose using dicyclopentadienylzirconium(0)-mediated oxygen abstraction from a furanose. Oxidative scission of the vinyl substituent of this cyclobutane gave an aldehyde, which was reacted with an alkynylstannane to provide an allenol. Cyclization of the derived allenone with silver nitrate led to a cyclobutylfuran comprising the northern subunit of providencin. The "southern" sector of the cembranoid skeleton containing a trisubstituted iodoalkene attached to an α-phenylselenyl-γ-lactone was synthesized from (R)-glycidol. Negishi carbometalation-iodination established the (E)-iodoalkene, and addition of the lithio dianion of phenylselenoacetic acid to a tosylate generated the substituted lactone. The two sectors were joined via stannylation of the furan of the northern component followed by Stille cross-coupling of the furylstannane with the iodoalkene of the southern subunit. Linkage of the two segments was also made at C12-C13 of providencin using intermolecular aldol condensation of the enolate from the selenyl lactone of the southern portion with an acetaldehyde appendage on the cyclobutane of the northern sector. Closure of the providencin macrocycle from these conjoined subunits was unsuccessful.

A salen ligand based on a chiral cis-2,5-diaminobicyclo[2.2.2]octane scaffold forms an iron(III) complex with ferric chloride which catalyzes asymmetric addition of thiols to α,β-unsaturated ketones under mild conditions. The reaction (sulfa-Michael addition) produces β-thioketones in excellent yield and high enantiomeric excess from a wide range of aliphatic and aromatic thiols using chalcones and other conjugated enones as Michael acceptors. With α-substituted α,β-unsaturated ketones as acceptors, the addition shows strong preference (typically >50:1) for the syn diastereomer over the anti product. An asymmetric synthesis of (R)-Montelukast, the sodium salt of which is the commercial anti-asthma drug Singulair®, was devised using conjugate addition of a thiol catalyzed by our iron(III)–salen complex to an α,β-unsaturated ketone synthesized in a four-component, one-pot tandem Michael-aldol condensation. The reaction sequence to (R)-Montelukast proceeded in 72% overall yield over four steps from commercially available materials. A mechanism for our catalyzed asymmetric sulfa-Michael addition is advanced which coordinates the enone acceptor to the metal centre of the iron–salen complex in an open lower quadrant under the bicyclic scaffold, thereby exposing only the si face of the double bond to attack by the external nucleophilic thiol. Prior internal coordination of the thiol to the metal centre of the complex is proposed based on spectroscopic and chemical evidence and leads to activation of the catalyst through a trans ligand effect.

The article deals with Bogdanov's thought in the period of the First World War and the Russian revolution, in particular with the evolution of his views on ‘proletarian culture.’ In contrast to Lenin and others who believed that modern capitalism had created the prerequisites for socialism, Bogdanov thought that the anarchy of the capitalist system remained and that a socialist society would have to be consciously created over a lengthy period of time. A related difference of opinion concerned the reasons why the Second International had collapsed on the outbreak of the war. Lenin's explanation was that the resolve of the socialist movement had been undermined by the presence in the advanced industrial countries of a ‘workers’ aristocracy' which participated in the profits of imperialist exploitation. Bogdanov believed that the capitulation of the socialist movement to war fever reflected the fact that bourgeois modes of thought had permeated the attitudes of the working class. In order to remedy this sit...

ConspectusCatalysis of widely used chemical transformations in which the goal is to obtain the product as a pure enantiomer has become a major preoccupation of synthetic organic chemistry over the past three decades. A large number of chiral entities has been deployed to this end, many with considerable success, but one of the simplest and most effective catalytic systems to have emerged from this effort is that based on a chiral diamine, specifically trans-1,2-diaminocyclohexane. While there have been attempts to improve upon this scaffold in asymmetric synthesis, few have gained the recognition needed to take their place alongside this classic diamine. The challenge is to design a scaffold that retains the assets of trans-1,2-diaminocyclohexane while enhancing its intrinsic chirality and maximizing the scope of its applications. It occurred to us that cis-2,5-diaminobicyclo[2.2.2]octane could be such a scaffold. Synthesis of this diamine in enantiopure form was completed from benzoic acid, and the (1R,2...

Catalysis of widely used chemical transformations in which the goal is to obtain the product as a pure enantiomer has become a major preoccupation of synthetic organic chemistry over the past three decades. A large number of chiral entities has been deployed to this end, many with considerable success, but one of the simplest and most effective catalytic systems to have emerged from this effort is that based on a chiral diamine, specifically trans-1,2-diaminocyclohexane. While there have been attempts to improve upon this scaffold in asymmetric synthesis, few have gained the recognition needed to take their place alongside this classic diamine. The challenge is to design a scaffold that retains the assets of trans-1,2-diaminocyclohexane while enhancing its intrinsic chirality and maximizing the scope of its applications. It occurred to us that cis-2,5-diaminobicyclo[2.2.2]octane could be such a scaffold. Synthesis of this diamine in enantiopure form was completed from benzoic acid, and the (1R,2R,4R,5R) enantiomer was used in all subsequent experiments in this laboratory. Condensation of the diamine with various salicyl aldehydes generated imine derivatives which proved to be excellent "salen" ligands for encapsulation of transition and other metals. In total, 12 salen-metal complexes were prepared from this ligand, many of which were crystalline and three of which, along with the ligand itself, yielded to X-ray crystallography. An advantage of this ligand is that it can be tuned sterically or electronically to confer specific catalytic properties on the salen-metal complex, and this feature was used in several applications of our salen-metal complexes in asymmetric synthesis. Thus, replacement of one of the tert-butyl groups in each benzenoid ring of the salen ligand by a methoxy substituent enhanced the catalytic efficiency of a cobalt(II)-salen complex used in asymmetric cyclopropanation of 1,1-disubstituted alkenes; the catalyst was employed in an improved synthesis of the cyclopropane-containing drug candidate Synosutine. Reduction of the pair of imine functions of the ligand to secondary amines permitted formation of a copper(I)-salen complex that catalyzed asymmetric Henry ("nitroaldol") condensation with excellent efficiency; this catalyst was applied in an economical synthesis of three drugs of the "beta-blocker" family including (S)-Propanolol. Chromium(II) and chromium(III) complexes were prepared from our bicyclooctane-salen ligand bearing a pair of tert-butyl groups in each benzenoid ring. These complexes were found to catalyze, respectively, enantioselective formation of homoallylic alcohols from Nozaki-Hiyama-Kishi allylation of aromatic aldehydes and dihydropyranones from hetero-Diels-Alder cycloaddition. Plausible reaction models emerging from knowledge of the absolute configuration of products from each of these reactions place the metal-coordinated substrate in a quadrant beneath the bicyclooctane scaffold so that one face of the substrate is blocked by an aryl ring of the salen ligand while the opposite face is left open to attack. The consistent and predictable stereochemical outcome from reactions catalyzed by salen-metal complexes derived from our diaminobicyclo[2.2.2]octane scaffold adds a valuable new dimension to asymmetric synthesis.

The NMR spectra of a number of naturally occurring alexines (tetrahydroxylated pyrrolizidine alkaloids) are analyzed and the consequences of changes in the configuration on the conformation of these bicyclic systems discussed. Unambiguous syntheses of australine (7-epi-alexine) and of 7,7a-epi-alexine have now unequivocally established the structures of two natural products isolated from Castanospermum australe which were insecure due to erroneous NMR data. Chemical shift parameters are unreliable as a method of comparing different samples of identical compounds; however, 1H–1H three bond coupling constants (3JHH) provide easy direct comparison between samples and allow assignments of both the relative configurations for the ring protons and the conformation of the pyrrolizidine framework.

A new chiral tetrahydrosalen ligand has been designed and synthesized from cis-2,5-diaminobicyclo[2.2.2]octane. The complex generated in situ by the interaction of the ligand with (CuOTf)(2)·C(6)H(5)CH(3) was an efficient catalyst for the asymmetric Henry reaction, producing nitroaldol products in high yield and good stereoselectivity. Henry reactions catalyzed by this tetrahydrosalen-Cu(I) complex led to syntheses of β-adrenergic blocking agents (S)-toliprolol, (S)-moprolol, and (S)-propanolol.

Chantier qualité GA; International audience; Legumes (Fabaceae or Leguminosae) are unique among cultivated plants for their ability to carry out endosymbiotic nitrogen fixation with rhizobial bacteria, a process that takes place in a specialized structure known as the nodule. Legumes belong to one of the two main groups of eurosids, the Fabidae, which includes most species capable of endosymbiotic nitrogen fixation1. Legumes comprise several evolutionary lineages derived from a common ancestor 60 million years ago (Myr ago). Papilionoids are the largest clade, dating nearly to the origin of legumes and containing most cultivated species2. Medicago truncatula is a long-established model for the study of legume biology. Here we describe the draft sequence of the M. truncatula euchromatin based on a recently completed BAC assembly supplemented with Illumina shotgun sequence, together capturing ~94% of all M. truncatula genes. A whole-genome duplication (WGD) approximately 58 Myr ago had a major role in shaping the M. truncatula genome and thereby contributed to the evolution of endosymbiotic nitrogen fixation. Subsequent to the WGD, the M. truncatula genome experienced higher levels of rearrangement than two other sequenced legumes, Glycine max and Lotus japonicus. M. truncatula is a close relative of alfalfa (Medicago sativa), a widely cultivated crop with limited genomics tools and complex autotetraploid genetics. As such, the M. truncatula genome sequence provides significant opportunities to expand alfalfa’s genomic toolbox.

The memoirs of Ivan Chugurin translated below are of interest because they are written by someone who lived through some of the most crucial moments in the history of the Russian revolutionary movement. Chugurin's narrative takes us through the 1905 revolution in Sormovo and Nizhnii Novgorod, culminating in the overthrow of the tsarist regime in February 1917. He is able to provide insights into the development of Social Democracy in Sormovo, the 1905 events there, the Longjumeau party school, and the part played by Bolshevik organisations in the February revolution. In his revolutionary career Chugurin made the acquaintance of several prominent figures in the Russian revolutionary movement and is in a position to describe his encounters with Lenin, Plekhanov, Sverdlov and Martov. What lends particular authenticity to these memoirs is that they are an unvarnished factual account of events, with very little in the way of ideological colouring. The memoirs, which appear to have been written in the 1920s, we...

Ivan Dmitrievich Chugurin was born in 1883 in the village of Sormovo near Nizhnii Novgorod, which was situated on the right bank of the river Volga. There in 1849 a major ship‐building and engineer...

A new C(2) symmetric salen scaffold based on cis-2,5-diaminobicyclo[2.2.2]octane has been synthesized that forms complexes with a wide range of metals. The chromium(III) complex is shown to catalyze the hetero-Diels-Alder reaction and the Nozaki-Hiyama-Kishi reaction with high efficiency and excellent stereoselectivity.

Conjugate reduction of an enone accompanied by in situ intramolecular aldol condensation was used to construct the tetrasubstituted cyclohexane nucleus of phomactins. Subsequent relay ring-closing metathesis completed the nine-membered ansa bridge of the diterpenoid framework.

We describe an undergraduate laboratory that combines an accurate measurement of the speed of light, a fundamental investigation of a basic laser system, and a nontrivial use of statistical analysis. Students grapple with the existence of longitudinal modes in a laser cavity as they change the cavity length of an adjustable-cavity HeNe laser and tune the cavity to produce lasing in the TEM$_{00}$ mode. For appropriate laser cavity lengths, the laser gain curve of a HeNe laser allows simultaneous operation of multiple longitudinal modes. The difference frequency between the modes is measured using a self-heterodyne detection with a diode photodetector and a radio frequency spectrum analyzer. Asymmetric effects due to frequency pushing and frequency pulling, as well as transverse modes, are minimized by simultaneously monitoring and adjusting the mode structure as viewed with a Fabry-Perot interferometer. The frequency spacing of longitudinal modes is proportional to the inverse of the cavity length with a proportionality constant equal to half the speed of light. By changing the length of the cavity, without changing the path length within the HeNe gas, the speed of light in air can be measured to be ($2.9972 \pm0.0002) \times 10^{8}$ m/s, which is to high enough precision to distinguish between the speed of light in air and that in a vacuum., Comment: 6 pages; 6 figures; Published in the American Journal of Physics

Irradiation of a tryptamine linked through its side-chain nitrogen to an alkylidene malonate residue results in an intramolecular [2 + 2] cycloaddition to the indole 2,3-double bond. The resultant cyclobutane undergoes spontaneous retro-Mannich fission to produce a spiro[indoline-3,3'-pyrrolenine] with relative configuration defined by the orientation of substituents in the transient cyclobutane. The tandem intramolecular photocycloaddition-retro-Mannich process, abbreviated as TIPCARM, leads to a spiropyrrolidine which is poised to undergo a second retro-Mannich fragmentation that expels the malonate unit and generates transiently an indolenine. The latter undergoes rearrangement to a beta-carboline, which upon brominative oxidation undergoes further rearrangement to an oxindole. With tryptamine as starting material, the entire sequence leads to the alkaloid (+/-)-coerulescine. Starting from 5-methoxytryptamine, a parallel series affords (+/-)-horsfiline. Modification of the malonylidene unit to include an isobutyl substituent at C3 affords a photosubstrate which also undergoes the TIPCARM process. In this case, a 2'-isobutyl-substituted spiro[indoline-3,3'-pyrrolenine] results. This undergoes stereoselective hydride reduction to give a product with relative orientation at the spiro carbon and the new stereocenter bearing the isobutyl appendage corresponding to that of the alkaloid elacomine. From tryptamine, the sequence paralleling that leading to coerulescine and horsfiline terminates at 6-deoxyelacomine, whereas 6-methoxytryptamine as starting material affords (+/-)-elacomine itself.

Two routes to the masked tricarbonyl segment of the immunosuppressant rapamycin comprising C8–C19 were explored beginning from d -xylose. The first approach employed a protected form of 2,4,5-trihydroxypentanol to obtain dithiane 43 , which failed to react with dimethyl oxalate to give a 1,2,3-tricarbonyl unit corresponding to the northern sector of rapamycin. A second approach employing carboxylic acid 61 derived from 43 utilized base-mediated (Chan) rearrangement of α-acyloxyacetate 62 with trapping of the resultant enediolate as bis silyl ether 63 . Epoxidation of this diene afforded masked tri-keto ester 65 which underwent acid-catalyzed methanolysis to produce cyclic ketal 67 .

The sector comprising C24–C34 of FK-506 containing five of the stereogenic centers in this macrolide was synthesized from (−)-quinic acid. Aldol coupling of the C24–C34 unit with a methyl ketone representing C20–C23 of FK-506 proceeded with complete Felkin stereoselectivity to afford the C20–C34 portion of the immunosuppressant. A chelate transition state invoking coordination of a lithium enolate with a trityl ether is proposed to explain this stereoselectivity. The strategy adopted for construction of the C26–C34 moiety of FK-506 was extended to the C34–C42 subunit of rapamycin. A Mukaiyama asymmetric anti -aldol coupling was used to set in place the vicinal diol functionality at C27,28 in the C26–C33 segment of this macrolide.

Biomimetic and other strategies that have been developed in theauthor’s laboratory for the synthesis of a subset of the groupof enzymically oxidized lipids known as oxylipins are described.This set of oxylipins contains both a cyclopropane and a lactone,with the lactone ring size varying between six and nine members.A biomimetic approach employing cascade cyclization of an epoxyalkenoicacid was successful in creating the cyclopropane and six-memberedlactone of C 20 oxylipins such as the constanolactonesin a single step, but failed in an attempt to create the nine-memberedlactone of halicholactone. Solandelactones, C 22 oxylipinscontaining a cyclopropane and an eight-membered lactone, were synthesizedby directed Simmons-Smith cyclopropanation followed byClaisen rearrangement of a cyclic ketene acetal to construct thelactone 1 Introduction 2 The First Biomimetic Cascade Synthesis of an Oxylipin 3 Biomimetic Cascade Synthesis of Constanolactones A and B 4 A Failed Biomimetic Strategy for Halicholactone 5 Synthesis of the C 22 Oxylipins SolandelactonesA, B, E, and F 5.1 A Ring-Closing Metathesis Approach to the Octenalactone Portionof Solandelactones 5.2 The Petasis-Claisen Rearrangement Route to theOctenalactone Portion of Solandelactones 6 Conclusion

Georgii Plekhanov is often credited with being the ‘father of Russian Marxism’. He was not, however, the first Russian Marxist. That distinction belongs to Nikolai Ivanovich Sieber (Ziber), whose dissertation on Marx’s economics appeared in 1871, the year before the Russian translation of Das Kapital, and introduced Plekhanov’s generation of Russian revolutionaries to Marxist ideas. Sieber’s work was then given a prominent endorsement in the second edition of Das Kapital, wherein Marx praised the depth of understanding Sieber had displayed of his economic theory. In view of this, one might consider that Sieber should be regarded as a dominant figure in the history of Marxism in Russia but, in fact, he is seldom mentioned by historians – and, when he is, it is generally cursorily and dismissively. The purpose of this article, therefore, is to examine the interrelationship of Sieber and Marx and to place Sieber’s writings in the context of the emergence of the Russian conception of Marxism at the end of the...