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A facile one-step synthetic approach to dihydrofuro-[3,2- c ]chromenones and furo[3,2- c ]chromenones by the reaction of methyl enol ethers with 4-hydroxycoumarins under metal-free conditions is presented. Dihydrofuro[3,2- c ]chromenones and furo[3,2- c ]-chromenones were selectively obtained by controlling the stoichiometry of boron trifluoride diethyl etherate. An unexpected aryl-group migration followed by aromatization of the furan moiety, leading to a variety of furo[3,2- c ]chromenone derivatives in good yields, is reported. [ABSTRACT FROM AUTHOR]

The first total synthesis of acylphloroglucinol-based natural products faberiones A, B, and E is reported, which were isolated from Hypericum faberi. Total syntheses of faberiones A and B are accomplished in six linear steps from commercially accessible 1,3,5-trimethoxybenzene (methyl protected form of phloroglucinol) in overall yields of 31 and 33% respectively, via simple and straightforward approaches that include acylation, o-methoxy deprotection, selective iodination and tandem-Sonogashira cyclization followed by C-geranylation. Faberione E is achieved in two linear steps from acylphloroglucinol with an overall yield of 57% via geranylation followed by benzopyran formation reaction. [ABSTRACT FROM AUTHOR]

An efficient approach for synthesizing fused nitrogen containing heterocycles has been formulated. The approach relies on the use of 2-bromo-3-(arylamino)-1H-inden-1-one derivatives as precursors for the synthesis of indenoindoles and indenoisoquoinolines. The synthesis of indenoindoles is achieved via palladium-catalyzed C-H activation strategy, while a sequential palladium-catalyzed intermolecular Suzuki coupling followed by an intramolecular annulation process is used to synthesize indenoisoquinolines. The developed strategy offers indenone fused polycycles in moderate to good yields. [ABSTRACT FROM AUTHOR]

A mild and transition‐metal‐free one‐pot strategy is established to prepare polysubstituted naphthalene and phenanthrene derivatives from methyl enol ethers (MEE) with alkynes. Significantly, this protocol is promoted by boron trifluoride diethyl etherate (BF3⋅Et2O) at room temperature. A wide variety of diversely functionalized naphthalene and phenanthrene derivatives were obtained in good to excellent yields. A plausible mechanism involving a spiro quinonoid intermediate is proposed. Due to fluorescent nature of naphthalene, selected compounds were screened for the solvatochromism study. Notably, positive solvatochromism effect was observed in the case of nitro‐substituted naphthalene derivative (3 h) with respect to different polarity of solvents. [ABSTRACT FROM AUTHOR]

Background: Xanthogranulomatous pyelonephritis (XGP) is chronic pyelonephritis subtype where in renal parenchymal destruction occurs and therefore results in progressive loss of kidney functions. Although middle age group is the predominant age group affected but it can be seen at any age. There is accumulation of macrophages (lipid-laden) leading to renal parenchymal destruction and fibrosis. In this study, we present our data of 15 patients who had undergone nephrectomy and were biopsy proven XGP. Aims and Objectives: The aim of the study was to describe the clinical and radiological features of XGP in adults. Materials and Methods: XGP constituted 4.31% of the 348 nephrectomies done for infective causes over a period of 7 years. All our patients had undergone unilateral total nephrectomy. Demographic and clinical records were analyzed after consent from all the patients. Results: The age range in our study was 18–65 years with mean 42.93±15.66 years. Nine of our patients, that is, 60% were females. Diabetes was present in 53.3% of our patients. Three patients had imaging suggestive of pyonephrosis, three patients had perinephric collection and 9 patients (60%) had concomitant nephrolithiasis. All the kidneys were grossly enlarged and were non-functional on renal scintigraphy. Conclusion: XGP is a form of chronic pyelonephritis which although being less common but is devastating given the destruction of renal parenchyma it does and associated morbidity. Clinicoradiologic correlation cannot be overemphasized. The definitive diagnosis is established after histopathologic examination. [ABSTRACT FROM AUTHOR]

[Display omitted] A simple yet efficient approach towards the synthesis of β -hydroxy selanylated ketones was developed from easily accessible chalcones and diphenyl diselenide through an electrochemical pathway. In this technique, diphenyl diselenide and water are the source of PhSe. and hydroxyl (–OH) groups that can be inserted at the α and β positions respectively producing β -hydroxy selanylated ketones in moderate to good yields. The reaction features difunctionalization of ketones, catalyst free, mild reaction conditions, stereo and regioselectivity in an undivided electrochemical cell at room temperature. For this transformation, a plausible radical mechanism has been put out. [ABSTRACT FROM AUTHOR]

A tandem, one-pot reaction of 2,3-dibromoindenone with phenols is reported, which provides a straightforward approach to accomplish structurally diverse indenobenzofurans in excellent yields. Besides, the control experiments revealed that reaction proceeds through a two-step sequence via an intermolecular Michael addition-elimination reaction, which enables the C-O bond formation, followed by palladiumcatalyzed intramolecular C-C bond formation through C-H activation. Significantly, this protocol offers a convenient approach to synthesize the diverse tetracyclic indenobenzofurans. [ABSTRACT FROM AUTHOR]

A full account of the total synthesis of (±)-cassumunins A–C – superior antioxidants and anti-inflammatory agents – is given. Two novel approaches were developed for synthesizing cassumunins. The total synthesis of cassumunins A and B was accomplished in five linear steps from a known aldehyde in good overall yields of 50 and 43%, respectively, featuring a cascade [3,3]-sigmatropic shift (the Claisen rearrangement) and Heck cross-coupling reaction. Consequently, the total synthesis of cassumunin C was accomplished in three linear steps from a known alcohol with an overall yield of 53%. The key features involved in this synthesis are tandem [3,3]-sigmatropic shift, SN 2′ reaction, and aldol condensation. Moreover, a total of eighteen symmetrical and unsymmetrical curcumin analogues were synthesized. [ABSTRACT FROM AUTHOR]

Abstract 1,6-Conjugate addition of various carbon nucleophiles to p -quinone methide surrogate is reported. The active methylene containing C -nucleophiles such as 1,3-diketones, diesters and ketoesters underwent two consecutive additions leading to bis-addition products, diarylpropanes. Whereas, nitroalkanes proceeded to contribute mono-addition products. Surprisingly, bromo analogue of p -quinone methide surrogate underwent halophilic dimerization reaction with excellent yield. The reported strategy provides an efficient synthesis of 1,3-diarylpropane derivatives bearing pharmacophoric ortho -methoxy phenol moiety under mild reaction conditions. Graphical abstract Image 1 Highlights • Two consecutive 1,6-conjugate additions of carbon nucleophiles to p -quinone methide surrogate is reported. • This strategy was found amenable to 1,3-ketoesters, diesters, diketones and nitroalkane compounds. • Wide substrate scope and good to excellent yields are reported under mild reaction conditions. • It is a novel strategy for the synthesis of 1,3-diarylpropanes bearing pharmacophoric ortho -methoxy phenol moiety. • Formation of an unexpected dimerized product through a halophilic reaction is reported. [ABSTRACT FROM AUTHOR]

Herein, DFT studies corroborating experimental results revealed that the shortest intramolecular hydrogen bonding distance of cis/trans‐oxaphosphetane (OPA) oxygen with the CH‐hydrogen of a triphenylphosphine phenyl ring provides good evidence for the attained olefin Z/E‐selectivity in Wittig olefination of the studied examples. 2‐Nitrobenzaldehyde, 3‐nitrobenzaldehyde, 2‐nitro‐3‐bromobenzaldehyde, 2‐nitro‐5‐bromobenzaldehyde and 2‐nitro‐5‐arylbenzaldehydes provided Z‐nitrostilbenes with (2‐chloro‐4‐hydroxy‐3‐methoxy‐5‐(methoxycarbonyl)benzyl) triphenylphosphonium chloride as the major products. However, 4‐nitrobenzaldehyde and 2‐nitro‐6‐bromobenzaldehydes furnished E‐nitrostilbenes as the major products in high yields. Furthermore, the DFT computed intramolecular CH1/CH2‐hydrogen bond distances with Cl/NO2 of selected stilbene derivatives were in good agreement with intramolecular hydrogen bond distances measured from single‐crystal X‐ray diffraction measurements. [ABSTRACT FROM AUTHOR]

We herein report a serendipitously observed acid mediated rearrangement of monoethylene ketal of 2-methyl-2-(3-methylbut-2-en-1-yl)cyclohex-4-ene-1,3-diones to Dihydrobenzopyran and demonstrated the application of this methodology in the construction of core carbon scaffolds of dimethoxyajacareubin, cariphenone-A and crotamadine. [ABSTRACT FROM AUTHOR]

The expeditious route for the synthesis of γ-butyrolactone fused cyclooctene starting from the γ-butyrolactone fused cyclopentane through bicyclo[4.2.1]nonan-9-one is reported. Retro-Dieckmann's condensation of bicyclo[4.2.1]nonan-9-one in presence of sodium methoxide and methanol furnished γ-butyrolactone fused cyclooctene in good yield. Surprisingly, the stereochemistry of ringjunction of γ-butyrolactone fused cyclooctene is different from the γ-butyrolactone fused cyclopentane, and the position of new ester group, which were confirmed unambiguously by X-ray analysis. [ABSTRACT FROM AUTHOR]

An efficient protocol for the synthesis of dihydrobenzoxazine and tetrahydrobenzoxazepine derivatives has been developed using haloarenes involving N -dealkylative S N Ar reaction. The method employs a wide variety of substrates and features the formation of C O and C N bonds in one-pot fashion. The products thus generated have been further transformed to m -terphenyls by using Suzuki coupling reaction. [ABSTRACT FROM AUTHOR]

1,6-Conjugate addition of variety of amines and phenols to cyclohexadienone derivative 1 directly leading to aryl benzyl amines and aryl benzyl ethers in excellent yield has been reported. The reaction proceeds via a sequential Michael type addition followed by aromatization. This methodology allows a facile and efficient synthesis of functionalized aryl benzyl amines and aryl benzyl ethers under mild conditions. [ABSTRACT FROM AUTHOR]

The formation of a twist-brendane via intramolecular enolate alkylation is described. Conversion of bicyclo[2.2.1]heptane scaffold present in this twist-brendane through a Grob-type fragmentation to unravel a functionalized bicyclo[2.2.2] system which contains all the necessary carbon atoms of the lipophilic core structure of nor-platencin, a platencin analogue is presented. Synthesis of core structure of platencin was also accomplished by extending this strategy to a starting material possessing a surrogate for the exocyclic methylene group. [ABSTRACT FROM AUTHOR]

A new role of superoxide ion in the isomerization of homobenzylic acetylenes leading to 1-aryl-1,3-butadienes is reported. The unconventional reagent KO 2 is found to be superior in performing this kind of isomerization over other the commonly used bases. For substrates containing arene moiety and triple bond connected through more than two methylene groups, and for propargylcyclohexanol the reagent selectively effected migration of the triple bond. Reactivity of KO 2 towards the substrates having disubstitution at benzylic position varied depending on the nature of the substitution, alkyl-substitution lead to isomerization to give mixture of allene (an intermediate in the isomerization of acetylene to 1,3-butadiene) and triple bond migration product; whereas phenyl-substituted compound gave 1,3-diene. The utility of the methodology was demonstrated through a Diels–Alder reaction of one of the dienes obtained by the isomerization with suitable dienophiles. [ABSTRACT FROM AUTHOR]

A selective debromination of tetracyclic dibrominated bis-γ- lactones in the presence of triethylamine and mesyl chloride is reported. Both mesyl chloride and triethylamine are essential for the debromination process. The reduction is proposed to proceed through halophilic substitution of electrophilic bromine. The source of the halophile in this reaction is believed to be triethyl(mesyl)ammonium chloride. The nonoccurrence of debromination in dibromo bis-γ-lactones with tosyl chloride and triethylamine as reagents suggests that the formation of a source of well-dissociated chloride ions during the reaction is necessary. Furthermore, selective debromination of dibrominated bis-γ-lactones was also achieved by using pyridine-thionyl chloride as a reagent. Alternatively, potassium chloride-[18-crown-6] was demonstrated to be a suitable source of chloride ion for the reduction of bromolactones. [ABSTRACT FROM AUTHOR]

A facile and efficient base promoted one-pot dimerization of halo cyclohexene derivatives leading to a de novo synthesis of biologically important diarylmethane and diarylmethanone derivatives is reported. A plausible mechanism for the unexpected formation of the title compounds involves dehydrohalogenation, 1,6-conjugate addition, subsequent aromatization through C–C bond cleavage and dehydrohalogenation. [ABSTRACT FROM AUTHOR]

An efficient and versatile synthesis of 3-alkenylbutenolides through direct Suzuki–Miyaura cross coupling reaction between preformed 3-halobutenolides and a range of readily accessible boronic acids has been devised. The coupling process exhibits good functional group compatibility and is preparatively viable. The methodology has been applied to achieve short syntheses of natural products rac -akolactones A & B and rac -hamabiwalactone B. The scope of the Suzuki–Miyaura reaction based protocol has been further amplified through the synthesis of 3,3′-alkenyl- bis -butenolides by employing α, ω- bis -boronic acids as coupling partners and applied to a synthesis of bioactive natural product rac -ancepsenolide. [ABSTRACT FROM AUTHOR]

The base-mediated formation of a bridgehead double bond in a bicyclo[2.2.1]heptane system (anit-Bredt molecules) is described. The synthesis of exocyclic norbornyl enones by Wittig reaction of α-diketones is reported. These enones and their Michael adducts are used as substrates for the generation of transient bridgehead enones and their trapping with MeOH and H2O. Bridgehead alcohols are easily synthesized from norbornyl enones and are exploited for the diversity oriented synthesis of frameworks of natural and unnatural products. [ABSTRACT FROM AUTHOR]

A diastereoselective zinc-mediated propargylation of non-enolizable norbornyl α-diketones and an efficient AgI-catalyzed cycloisomerization of the resulting α-keto homopropargyl alcohols with terminal alkynes leading to spirocyclic dihydrofurans have been reported. The dihydrofurans obtained were subjected to hydrogenation to afford spiro tetrahydrofuran derivatives in nearly quantitative yields (98-99 %). Eventually, the prepared α-spiro tetrahydrofuran norbornyl monoketones were utilized as precursors for acid-mediated Grob-type fragmentation reactions and converted into 1-oxaspiro[4.5]decan-6-one derivatives by treatment with p-toluenesulfonic acid. [ABSTRACT FROM AUTHOR]

A macrocyclic furanobutenolide was crafted from readily available furan building-blocks to set-up a transannular Diels–Alder reaction which delivered the carbocyclic core present in a class of cembranoid diterpene natural products. [ABSTRACT FROM AUTHOR]

Total syntheses of two antimicrobial natural products (±)-cis-neocnidilide and (±)-trans-neocnidilide starting from a readily preparable cyclohexa[b]-fused 5-oxabicyclo[2.1.1]hexane derivative are presented. The diastereomeric tetrahydrofuran tricarboxylate epimers obtained from a BF3⋅OEt2 promoted Grob-type fragmentation of the oxa-bicycle derivative were converted into title natural products by employing pyridinium dichromate/acetic anhydride mediated bis-oxidative cleavage reaction. [ABSTRACT FROM AUTHOR]

Abstract: A formal synthesis of marine-derived antitumor natural product varitriol from a 5-oxabicyclo[2.1.1]hexane derivative is described. A tetrahydrofuran unit of varitriol embedded with four contiguous stereocenters was synthesized with an overall yield of 10.2% in 11 steps from an oxa-bicyclic system. An unprecedented oxidative cleavage reaction involving scissoring of two C C bonds at oxa-quaternary carbon of THFs leading to γ-butyrolactones was reported and a plausible mechanism has been proposed. [Copyright &y& Elsevier]

An unusual route for the synthesis of functionalized cyclobutane derivatives starting from functionalized norbornane derivatives is reported. Base-induced fragmentation of an oxetanol-type moiety embedded in a tetracyclic norbornyl ketal leads to a cyclobutane-fused derivative as the major or exclusive product. The fragmentation reaction for bridgehead-bromine-substituted derivatives was much faster than for the corresponding chlorine-substituted substrates. The functionalized cyclobutane product was formed exclusively in high yield in the former case, while the latter furnished a minor uncyclized side product in varying yields. [ABSTRACT FROM AUTHOR]

Abstract: Acid mediated, efficient Grob-type fragmentation reaction facilitated by vicinal ketal and ester moieties in variety of 5-oxabicyclo[2.1.1]hexanes leading to the corresponding annulated and 2,2,5-trisubstituted tetrahydrofurans is reported. Among the Brønsted and Lewis acids tested, BF3·OEt2 appears to give the best results, furnishing near quantitative yield (>99%) of tetrahydrofuran tricarboxylate derivatives under mild reaction condition. In case of unsymmetrical monosubstituted 5-oxabicyclo[2.1.1]hexanes two regioisomeric products are obtained. A strategy to transform one of the ester groups of the title compounds to protected hydroxymethyl moiety was evolved, which allows access to differentially protected 2-hydroxymethyl THF derivatives upon fragmentation. Employing TiCl4/R or S-BINOL as chiral Lewis acid, an enantioselective fragmentation (up to 66% ee) was described for the meso bis-furan derivative. [Copyright &y& Elsevier]

Abstract: A total synthesis of bioactive tetracyclic natural product paracaseolide A, embodying an architecturally unusual oxa-bowl framework, has been accomplished from commercially available 5-methyl-2-furfural. The key step involving a thermal [4+2]-dimerization of an appropriately crafted 5-methyl-3-alkenylbutenolide is shown to proceed in a stepwise manner. [Copyright &y& Elsevier]

Total synthesis of the published structure of amathamide D is described. Methyl 2,3,4-tribromo-5-hydroxybenzoate was selected as starting compound because it is readily accessible via acid-mediated Grob fragmentation--aromatization reaction of 1,4,5,6-tetrabromo-7,7-dimethoxybicyclo[2.2.1]hept-5-en-2-one. The aforementioned ester was transformed into the reported structure of amathamide D through methylation of a hydroxyl group and conversion of the ester moiety to a β-aminoethyl side chain. The NMR data of the synthetic compound did not conform to the reported natural product structure possessing contiguously positioned β-aminoethyl side chain, a set of three adjacent bromines, and a methyl ether linkage on the phenyl ring. This prompted us to redeBne the natural product structure by synthesizing a product whose spectral data exactly matched with the reported data of amathamide D. The convolutamine H, with completely substituted phenyl ring adorned with an extra methyl ether functional group, has also been synthesized by application of Grob fragmentation--aromatization strategy to 3-(benzyloxy)-1,4,5,6-tetrabromo-7,7- dimethoxybicyclo[2.2.1 ]hept-5-en-2-one. This approach furnished directly methyl 2,3,4-tribromo-5,6-dimethoxybenzoate, which was converted straightforwardly into convolutamine H. Further, synthesis of convolutamine F and lutamide A and C is also described. [ABSTRACT FROM AUTHOR]

A racemic cyclopentannulated pyrrolidine derivative was synthesized utilizing ruthenium oxidation and borane reduction as the key steps. Ruthenium oxidation reaction of the 1,2-dibromoalkene moiety in an N-Boc-protected tetrabromonorbornyl derivative afforded a tricyclic α-hydroxy ketone, which on alkaline hydrogen peroxide cleavage furnished a bicyclic lactam in excellent yield. Borane reduction of the N-Boc-protected bicyclic lactam gave an unexpected product as a single diastereomer resulting from the reduction of not only the lactam and ester moieties but also the ketal to the corresponding methyl ether. A plausible mechanism involving an oxocarbenium ion is discussed. [ABSTRACT FROM AUTHOR]

An efficient acid-catalyzed Grob fragmentation of symmetrical and asymmetrically substituted norbornyl a-diketones to the corresponding six-membered a-ketoenols is reported. The regio- and stereochemical outcome of the Grob fragmentation of C2 mono- and disubstituted a-diketones was investigated. A single regioisomer resulting from a favorable half-chair intermediate was normally observed. A departure from the normal course was noticed for C2 disubstituted a-diketones possessing an exo-methyl and an endo-methoxycarbonyl derivative, giving the opposite regioisomers due to initial formation of the hemiketal. The bromo analogues of the C2 disubstituted a-diketones furnished an unusual byproduct, which appears to have been formed through highly reactive fused four-membered bicyclo[2.2.0]hexane intermediates. A plausible mechanistic proposal involving the gem-dihalo intermediate, which in one case was actually isolated as its BF2-complex, is outlined. The fragmentation protocol was applied to various norbornyl substrates including bis-a-diketone derivatives. The methodology was successfully utilized for the synthesis of substituted aromatic compounds. [ABSTRACT FROM AUTHOR]

Abstract: Several symmetrical, linear dimers and some star-like tetramers were prepared using easily accessible oxa-bridged derivatives as central rigid cores. In order to produce new liquid crystalline materials various mesogenic/promesogenic groups, containing biphenyl-4,4′-diol, 4,4′-(diazene-1,2-diyl)diphenol and cholesterol sub-moieties, were connected through oxy-ethylene linkers via an ester linkage, in the end-on fashion. Their thermal behaviour and mesomorphic properties were investigated by differential scanning calorimetry (DSC), polarized optical microscope (POM), and variable temperature small-angle X-ray diffraction (XRD) methods. While essentially all the biphenyl-4,4′-diol- and 4,4′-(diazene-1,2-diyl)-based dimeric derivatives exhibited smectic liquid crystalline mesophases, the nature of which are mesogenic groups dependent, none of the cholesterol-containing compounds and tetramers were mesomorphic. [ABSTRACT FROM AUTHOR]

Abstract: A facile transformation of pentasubstituted tribromophenol derivatives to the corresponding alkyl-substituted dibromo-p-benzoquinones has been achieved using PbO2 as oxidizing agent in combination with 60% aq HClO4 in acetone in 70–72% yields. The electrochemical properties of these quinones were studied by means of cyclic voltammetry and compared with p-benzoquinone (BQ) and 2,3-dichloro-5,6-dicyano-benzoquinone (DDQ) recorded under identical experimental conditions. [Copyright &y& Elsevier]

Efficient reduction of mono- and disubstituted norbornyl a-diketones with zinc in [bmimBF4]:[H2O] to afford the corresponding acyloins in excellent yields and diastereoselectivities is described. In case of the monosubstituted norbornyl α-diketones, very high regioselectivities ranging from 90:10 to 100:0, in favor of diastereomer possessing endo-hydroxyl diagonal to endo-substituent were observed. [ABSTRACT FROM AUTHOR]

Abstract: Nucleophilic racemic amines have been synthesized utilizing a C7nC5x free-radical cascade reaction from a bis-allyl amine starting material. Being potentially useful organocatalytic bases as is evident from their screening in the Baylis–Hillman reaction, optically pure amines were also synthesized from optically pure aldehydes (−) or (+)-4. Bis-allyl amides under similar radical reaction condition resulted in C7n cyclized products. [Copyright &y& Elsevier]

Abstract: Palladium(II)-catalyzed oxidative cyclization of methyl 2-allyl-4,5,6-tribromo-3-hydroxybenzoate 4 gave a mixture of methyl 5,6,7-tribromo-2-methyl-benzofuran-4-carboxylate 5 and methyl 6,7,8-tribromo-2H-1-benzopyran-5-carboxylate 6; the ratio of the two products varied between 71:29 and 24:76 depending on the reaction conditions. On the other hand, NBS or NIS mediated cyclization of 4 followed by treatment with NaOMe or DBU furnished benzofuran derivative 5 in good overall yield. [Copyright &y& Elsevier]

Abstract: An efficient stereoselective synthesis of both the diastereomers of diquinane-based conformationally constrained symmetric bis-γ-lactones starting from tricyclic derivative 9 is reported. The key step involves the intramolecular ring opening of an epoxide by the in situ formed hydrate of a diketone leading to the tetracyclic hemiacetal 10, which directly leads to the exo-hydroxy bis-γ-lactone derivatives 2 and 4 under basic hydrogen peroxide cleavage conditions. Conversion to the endo-hydroxy bis-γ-lactone derivatives 1 and 3 was accomplished through lithium hydroxide mediated SN2 displacements in dimesylate 7, or more expeditiously, via trimesylate 21 through alkaline H2O2 mediated cleavage. [Copyright &y& Elsevier]

Abstract: A new reaction of diazomethane with norbornyl α-diketones in MeOH as solvent leading regioselectively to ketals is described. The mechanistic details of this intriguing reaction were investigated employing d 4-MeOH, EtOH and d 6-EtOH. The surprising observation of complete deuterium incorporation in the diazomethane-derived methoxy group was accounted for by sequential deuterium exchange between the initially formed hemiketal d 4-18 and diazomethane in the presence of d 4-MeOH as solvent. [Copyright &y& Elsevier]

A stereoselective strategy for the replacement of the 1,2-dihaloalkene bridge of tetrahalonorbornyl derivatives by an oxygen bridge involving stepwise controlled oxidation, cleavage of the dione thus formed, and reiterative intramolecular SN2 displacement of two bridgehead halogens is devised. The synthesis of four highly strained pentacyclic bis-oxa-bridged derivatives 10, 27, 28, and 29 with interesting structural variations is presented. The two oxa bridges are syn to each other, separated by central cyclohexane and cycloheptane rings in 10 and 27, while they are anti to each other and are separated by central cyclopentane and furan rings in 28 and 29. In the case of the highly symmetric bis-oxa-bridged derivative 10 the two syn oxa bridges constrain the central cyclohexane ring into the boat form. The endo,anti,endo 2:1 bis adducts of 1,2,3,4-tetrahalo-5,5-dimethoxycyclopenta-l,3-diene with cyclopentadiene were prepared for the first time, while the reactivites of previously unexplored bis adducts derived from furan and cycloheptatriene were revealed. [ABSTRACT FROM AUTHOR]

Abstract: A highly efficient, recyclable layered double hydroxide (LDH)-supported ruthenium catalyst system (Ru-LDH) was developed for the facile transformation of 1,2-dihaloalkene moieties in tetrahalonorbornyl derivatives to the corresponding α-diketones. The efficiency of other supports such as LDH containing ruthenium(III) in a brucite layer (Ru–Mg–Al), commercial MgO (Ru–MgO), and montmorillonite K-10 (Ru-mont) was evaluated. Our results demonstrate that Ru-LDH and Ru–MgO are equally efficient, and the best turnover number (TON) reached was 5389. For NaIO4 as the co-oxidant, MeCN-H2O was the best solvent, whereas 1,2-dichloroethane/MeCN in a ratio of 5:1 gave superior results for NaOCl (household bleach). [Copyright &y& Elsevier]

A short and stereoselective route to the trans-hydrindane derivative, a potential building block for the synthesis of steroidal and related molecules, was achieved by the operation of indium, tin, and ruthenium based reagents, starting from a tetrabromo norbornyl derivative. [ABSTRACT FROM AUTHOR]

Knoevenagel condensation proceeds efficiently in recyclable [bmim]PF6 and [bmim]BF4 without any catalyst, and hydrotalcites in ionic liquid serve as a safe and recyclable reaction system for both Knoevenagel as well as nitroaldol condensations. [Copyright &y& Elsevier]

Nitroarenes were chemoselectively reduced to the corresponding amines using zinc and aqueous ammonium salts in ionic liquids as a safe and recyclable reaction medium. Our results specify the effect of ammonium salts in the process; the combination of Zn/NH4Cl in [bmim][PF6] or Zn/HCO2NH4 in [bmim][BF4] were the suitable conditions for the reduction of nitroarenes. Azobenzenes were also smoothly reduced to hydrazobenzenes with Zn/HCO2NH4 (aq.) in recyclable [bmim][BF4] without any over reduction to the corresponding anilines. [Copyright &y& Elsevier]

A rapid access to 7-azaspiro[4.5]decan-6-ones 1 involving three regio- and chemoselective reactions starting from tetrabromonorbornyl derivatives is described. The alkaline H[sub 2]O[sub 2] cleavage reaction of monosubstituted α-diketones 9 furnished the potential bridged bicyclic lactones 10 in a highly regio- and stereoselective manner. The radical-mediated, intermolecular bridgehead C-C bond formation of the versatile bridged lactones 10 with acrylonitrile followed by LAH reduction of the adduct 13 intriguingly leads to the formation of novel spirolactam building blocks 1. [ABSTRACT FROM AUTHOR]

Examines the method for easy access to γ-lactone-fused cyclopentanoids. Use of lead and alkaline to cleave the tricyclic α-keto hemiacetals; Elaboration of α-keto hemiacetal 3b to spiroepoxide derivative; Transformation of α-halo ester moiety.

Background: Peyronie's disease (PD) is a localized fibrosis of tunica albuginea, which causes the anatomical and functional changes to the penis. Corporoplasty with grafting is indicated in severe (>60°) and complex curvature. Buccal mucosa is the most favored autologous graft material nowadays. The ventrolateral aspect of lingual mucosa has similar histological features to the rest of the oral cavity. Methods: This study aimed to test the efficacy, safety, durability, and reproducibility of corporoplasty with lingual mucosal graft (LMG) in the surgical treatment of PD in terms of surgical outcome, sexual function, and donor site complications. This prospective study included 19 patients of PD with severe and complex curvature, who underwent corporoplasty with LMG. Surgical and functional outcomes were assessed at follow-up planned at 2 weeks, 3 months, 6 months, 1 year, and 2 years. Results: The mean operative time was 126.31 ± 21.45 min. Additional Nesbit's plication to correct the residual deformity was required in 26% (5 / 19) of patients. Straightening of the penis (curvature <10°) was achieved in 89% (17 / 19) of patients. Increase in the penile length (>1 cm) postoperatively was achieved in 63% (12 / 19) of patients and a shortening of penis occurred in 5% (1 / 19) of patients. Newer onset erectile dysfunction developed in 11% (2 / 19) of patients, and patient and partner satisfaction rates were 89% (17 / 19) and 84% (16 / 19), respectively, in a mean follow-up of 20.66 ± 5.37 months. Donor site complications were minimal and no patient had any salivary changes or speech disturbances. Conclusion: LMG provided excellent short-term results in terms of deformity correction, improved sexual function, and minimal donor site morbidity. The method is simple and reproducible, and multicenter studies with larger number of cases with longer follow-up are required to confirm these favorable results. [ABSTRACT FROM AUTHOR]

• FeCl 3 catalyzed C C, C N bond formation between methyl enol ethers and anilines. • 2,3-Disubstituted indole formation via aryl group migration. • Anilines act as bis-nucleophiles. An intermolecular FeCl 3 catalyzed reaction between anilines and enol ethers is described. A variety of enol ethers and aromatic amines undergo a C C bond formation followed by cyclization via C N bond formation to afford the 2,3-disubstituted indoles, involving an unexpected aryl group migration. In this methodology, anilines act as bis-nucleophiles, wherein the initial attack occurs at the α-position of enol ether from the ortho position of aniline followed by the subsequent reaction of the amine moiety of aniline at the β-position, leading to the indole framework. This method is simple, obviates the use of expensive/hazardous transition-metal catalysts, and offers a wide range of substrate scope. [ABSTRACT FROM AUTHOR]

Abstract: A two-step synthesis of marine origin brominated alkaloids wilsoniamines A (1) and B (2), isolated from Australian bryozoan Amathia wilsoni Kirkpatrick, possessing a novel hexahydro-1H-pyrrolo[1,2-c]imidazol-1-one ring system is described. The core hexahydro-1H-pyrrolo[1,2-c]imidazol-1-one ring systems is constructed through a condensation reaction between (2,4,6-tribromo-3-methoxyphenyl)acetaldehyde and (S)-N-methylpyrrolidine-2-carboxamide as key steps. The orientation of substituted benzyl side-chain in the two epimeric natural products was controlled by carrying out the key condensation reaction under kinetic or thermodynamic conditions. [Copyright &y& Elsevier]

Abstract: A simple protocol for the synthesis of an aesthetically pleasing ‘oxa-basket’ (5-methoxy-2,8,13-trioxapentacyclo[7.2.1.1.5,120.4,1106,10]tridecane-3,7-dione), possessing 9-oxa-noradamantane core, is described. The readily available diquinane based dichloro bis-γ-lactone precursor upon treatment with MeSO3H furnished dichloro ‘oxa-basket’ which was dechlorinated using TBTH/AIBN to obtain the title compound. The key role of the chlorines was demonstrated by replacement with hydrogen or allyl substituents which redirects the cascade to simple hydrolysis products. [Copyright &y& Elsevier]

Abstract: A simple and useful protocol for the reduction of nitro arenes to their corresponding azoxy derivatives by employing zinc and NH4Cl in a mixture of [bmim][BF4] and water is described. The selective reduction of nitro to azoxy is attributed to the hitherto unknown moderating effect of oxygen on zinc metal. [Copyright &y& Elsevier]