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The aim of the present study was to determine a suitable procedure for the treatment of chest wall neoplasms with less potential risk and an increased rate of survival. Fifty patients with suspected chest wall malignancies were analyzed using various preliminary investigation tools. Whole-chest scanning was performed in all the patients. The patients were subsequently subjected to biopsies for further confirmation of the neoplasm. All such patients were then treated with a surgical approach and radiation therapy, with a follow-up period lasting up to six years. The majority of the patients showed improved survival rates relative to conventional therapies. The survival rates of patients suffering from osteosarcoma (78%) were higher those of patients with rhabdomyosarcoma (73%) and malignant small round cell tumors (64%). The survival and the mortality rates of the patients with synovial sarcoma and fibrosarcoma were the same. This study, which was conducted on a small group of patients, has provided guidance for further studies on tumors of the chest wall, which may, in turn, increase the longevity of affected patients. [ABSTRACT FROM AUTHOR]

Although catalytic asymmetric synthesis has undergone tremendous growth in the last 30 years, chiral auxiliary-aided asymmetric synthesis continues to attract considerable attention. Chiral N- tert-butanesulfinamide, as pioneered by Ellman and co-workers, is undoubtedly one of the most efficient auxiliaries developed to date; it allows the preparation, through simple conversion, of a diverse range of enantiopure amines, which are ubiquitous in natural products and biologically active molecules. Following on from our studies of the SmI 2-mediated asymmetric syntheses of α,γ-substituted γ-butyrolactones, we found that simple homocoupling of chiral N- tert-butanesulfinyl imines in the presence of SmI 2produced enantiopure vicinal C2-symmetric diamines in high yield. In addition, C2-unsymmetric chiral diamines are readily prepared through SmI 2-mediated cross-couplings of N- tert-butanesulfinyl imines and nitrones; these transformations represented the first successful examples of asymmetric cross-coupling between two different imine species. Subsequently, we discovered another useful reaction induced by SmI 2, the efficient cross-coupling of N- tert-butanesulfinyl imines and aldehydes, which provides ready access to enantiopure anti-1,2-amino alcohols. The synthetic applicability of this reaction was demonstrated through its use in the facile total syntheses of (3 R,4 S)-statine, d- erythro-sphinganine, (+)-CP-99,994, and (+)-L-733,060. [ABSTRACT FROM AUTHOR]

Describes a reagent system for modified Ullmann-type coupling reactions. Proposed mechanism for the formation of C and E in polar solvent; Varieties of reaction conditions; Homocoupling of some substrates.

Describes the synthesis of optically pure 5,5''-dihydroxy-4,4''',7,7''-tetramethoxy-8,8''-biflavone and its dimethyl derivative. Resolution of the racemic form; Assignment of absolute configurations; Confirmation of configuration by X-ray single crystal analysis and from circular dichroism data; Synthetic mechanism.

A palladium-catalyzed disilylation reaction applicable for a variety of non-, α-, or β-substituted and α,β-disubstituted ortho-halophenylethylenes has been developed. This reaction proceeds with high yields and very low catalyst loadings. The two C–Si bonds of the disilylated products could be well-differentiated chemoselectively in the reaction with various electrophiles. [ABSTRACT FROM AUTHOR]

The article presents a study which reported a small molecule-catalyzed asymmetric rearrangement of cyclopropylcarbinyl cations, leading to a series of chiral homoallylic sulfide products with good to excellent yields and enantioselectivities. Topics discussed include reaction development and optimization, screening of substrate scopes, and mechanistic consideration.

Although much empirical evidence has demonstrated that p53 plays a key role in tumor suppression, the dynamics and function of the regulatory network centered on p53 have not yet been fully understood. Here, we develop a Boolean network model to reproduce the two-phase dynamics of the p53 network in response to DNA damage. In particular, we map the fates of cells into two types of Boolean attractors, and we find that the apoptosis attractor does not exist for minor DNA damage, reflecting that the cell is reparable. As the amount of DNA damage increases, the basin of the repair attractor shrinks, accompanied by the rising of the apoptosis attractor and the expansion of its basin, indicating that the cell becomes more irreparable with more DNA damage. For severe DNA damage, the repair attractor vanishes, and the apoptosis attractor dominates the state space, accounting for the exclusive fate of death. Based on the Boolean network model, we explore the significance of links, in terms of the sensitivity of the two-phase dynamics, to perturbing the weights of links and removing them. We find that the links are either critical or ordinary, rather than redundant. This implies that the p53 network is irreducible, but tolerant of small mutations at some ordinary links, and this can be interpreted with evolutionary theory. We further devised practical control schemes for steering the system into the apoptosis attractor in the presence of DNA damage by pinning the state of a single node or perturbing the weight of a single link. Our approach offers insights into understanding and controlling the p53 network, which is of paramount importance for medical treatment and genetic engineering. [ABSTRACT FROM AUTHOR]

In this paper, Ti–C–N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions, microstructures, and mechanical properties of the Ti–C–N films are investigated systematically by field emission scanning electron microscopy (FE-SEM), x-ray photoelectron spectroscopy (XPS), grazing incident x-ray diffraction (GIXRD), Raman spectra, and nano-indentation. The results show that the nanocrystalline Ti(C,N) phase precipitates in the film from GIXRD and XPS analysis, and Raman spectra prove the presence of diamond-like carbon, indicating the formation of nanocomposite film with microstructures comprising nanocrystalline Ti(C,N) phase embedded into a diamond-like matrix. The nitrogen flow rate has a significant effect on the composition, structure, and properties of the film. The nano-hardness and elastic modulus first increase and then decrease as nitrogen flow rate increases, reaching a maximum of 34.3 GPa and 383.2 GPa, at a nitrogen flow rate of 90 sccm, respectively. [ABSTRACT FROM AUTHOR]

This account summarizes our efforts on the design, synthesis, and application of two classes of chiral diene ligands bearing bicyclo[3.3.0]octadiene or dicyclopentadiene skeletons. These chiral diene ligands can be readily prepared from inexpensive commercial materials with enzymatic resolution as the key synthetic step. The ligands have been successfully applied in some rhodiumcatalyzed reactions, including 1,4-addition to a,b-unsaturated carbonyl compounds, arylation of imines, and conjugate addition to nitroalkenes. In addition, they have been used in the first successful palladium-diene-catalyzed asymmetric reaction. [ABSTRACT FROM AUTHOR]

The addition of alkynylmagnesium chlorides to N-tert-butanesulfinyl imines proceeded with a remarkably high diastereoselectivity (dr> 13:1, mostly diastereopure), and with a general scope of both reaction partners. The high dr translated into simplified purification and higher optical purity for the synthesis of a wide array of chiral a-branched amines. The alkyne functionality also provides a multitude of opportunities for further synthetic transformations. The short asymmetric synthesis of (+)-angustureine 7 and (-)-cuspareine 10 was realized with use of this approach. [ABSTRACT FROM AUTHOR]

A new diamine ligand for asymmetric transfer hydrogenation (ATH) was discovered. The reductive cyclization of 2-acylarylcarboxylates was found to proceed highly stereoselectively by the new Ru complex-catalyzed ATH and subsequent in situ lactonization under aqueous conditions. It enables efficient access to a wide variety of 3-substituted phthalides in enantiomerically pure form. [ABSTRACT FROM AUTHOR]

Intramolecular nucleophilic acyl substitution of highly functionalized β-amino-alkenyllithium species provided facile access to α-alkylidene aza-cycloketones with defined olefin geometry and rich structural diversity. A concise total synthesis of allopumiliotoxin 267A has been accomplished in 5 steps from 4 featuring this key transformation. [ABSTRACT FROM AUTHOR]

A new entry for the asymmetric synthesis of optically active α,γ-substituted γ-butyrolactones was developed by using a carbohydrate-derived amide as both a chiral auxiliary and a proton source. Unlike the previously reported examples, the chiral auxiliary employed in this reaction also successfully functioned as a protonating agent. Excellent asymmetric induction could be achieved by this dual stereoselective control in the reaction process. [ABSTRACT FROM AUTHOR]

An efficient access to cis-hydrobenzo[b]oxepine frameworks has been established through rhodium(I)-catalyzed cyclization of cyclohexadienone-tethered o-tolyl-substituted alkynes (1,6-enynes). The cascade process involves regioselective α-arylrhodation of the alkyne, 1,4-rhodium migration, and conjugate addition to cyclohexadienone. [ABSTRACT FROM AUTHOR]

An amine-promoted (4+3) annulation of δ-acetoxy allenoate with o-diaminobenzene is reported, providing a facile access to 1,5-benzodiazepine. This method features wide reaction scope, mild conditions, and readily available starting materials. The cascade reaction involves aza-Michael addition of o-diaminobenzene to allenoate, elimination of acetate group, and subsequent 1,6-aza-Michael addition. [ABSTRACT FROM AUTHOR]

The highly enantioselective preparation of spirooxindoles bearing α,α-disubstituted α-amino-β-keto esters was achieved through [4 + 1] annulation of oxindoles and α-imine-β-oxo-γ,δ-unsaturated esters under mild conditions in good yields (up to 82%) and stereoselectivities (up to >20:1 dr, 96% ee). The reaction is amenable to gram scale synthesis using catalyst loading as low as 1 mol %. The corresponding chiral α,α-disubstituted α-amino-β-keto esters could be easily transformed into cyclopenta[b]indole derivatives without erosion of enantiopurity. [ABSTRACT FROM AUTHOR]

The diastereoselective bisannulation of N-(pivaloyloxy)benzamides and cyclohexadienone-tethered allenes was accomplished through Cp*Rh(III)-catalyzed C-H activation and relay ene reaction, providing a 3-isoquinolonyl cis-hydrobenzofuran framework with high yields and diastereoselectivities. This reaction tolerates a wide range of functional groups, enabling further conversions to tricyclic and bridged-ring structures. Moreover, the dearomatization modification of phenol-contained bioactive molecule is also elaborated. [ABSTRACT FROM AUTHOR]

An efficient and step-economical approach to access functionalized pyrrolizidine derivatives by a one-pot tandem sequence, including an aldol condensation and subsequent 1,3-dipolar cycloaddition process, has been developed, starting from acetone, aldehyde, and proline. A number of substituted aromatic aldehydes were amenable to this transformation, and the desired products, racemic 7a-7w and chiral 9a-9m, were obtained with excellent regioselectivities and outstanding diastereoselectivities. Moreover, in situ NMR studies revealed MgSO4 could effectively promote the aldol condensation pathway in this tandem process. [ABSTRACT FROM AUTHOR]

The CuH-catalyzed asymmetric intramolecular reductive coupling of allenes to enones is successfully realized, providing cis-hydrobenzofurans with promising yields and excellent enantioselectivities. Such brilliant enantioselectivities are partially contributed by CuH-catalyzed favorable kinetic resolution of the cyclization products. This protocol tolerates a broad range of functional groups, allowing for further construction of tricyclic and bridged-ring structures. Moreover, the meta-chiral functionalization of 4-substituted phenol and asymmetric dearomatization modification of phenol-contained bioactive molecules are also described. [ABSTRACT FROM AUTHOR]

In this report, the originally proposed rupestonic acid (5) and pechueloic acid (3) were efficiently synthesized. The chiral lactone 13, recycled from the degradation of saponin glycosides, was utilized to prepare the key chiral fragment 11. During the exploration of this convergent assembly strategy, the ring-closing metathesis (RCM), SmI2-prompted intermolecular addition, and [2,3]-Wittig rearrangement proved to be effective transformations for the synthesis of subunits. [ABSTRACT FROM AUTHOR]

An efficient, enantioselective rhodium-catalyzed addition of potassium alkenyltrifluoroborates to N-nosyl aliphatic imines has been realized. Good reaction yields and excellent enantioselectivities (94-99% ee) were obtained for a variety of aliphatic imines and nucleophilic alkenyltrifluoroborates. An active rhodium-diene catalyst and the precise reaction condition control proved to be pivotal for success. [ABSTRACT FROM AUTHOR]

In this report, originally proposed apratoxin E (30S-7), revised apratoxin E (30R-7), and (30S)/(30R)-oxoapratoxin E (30S)-38/(30R)-38 were efficiently prepared by two synthetic methods. The chiral lactone 10, recycled from the degradation of saponin glycosides, was utilized to prepare the key nonpeptide fragment 9. Our alternative convergent assembly strategy was applied to the divergent synthesis of revised apratoxin E and its three analogues. Moreover, ring-closing metathesis (RCM) was for the first time found to be an efficient strategy for the macrocyclization of apratoxins. [ABSTRACT FROM AUTHOR]

An efficient method for asymmetric synthesis of apratoxin E 2 is described in this report. The chiral lactone 8, recycled from the degradation of saponin glycosides, was utilized to prepare the non-peptide fragment 6. In addition to this "from nature to nature" strategy, olefin cross-metathesis (CM) was applied as an alternative approach for the formation of the double bond. Moreover, pentafluorophenyl diphenylphosphinate was found to be an efficient condensation reagent for the macrocyclization. [ABSTRACT FROM AUTHOR]

The practical asymmetric synthesis of amathaspiramides B, D, and F has been accomplished by utilizing an aza-Barbier allylation as the key step to construct the common intermediate with two adjacent stereocenters. A kinetically controlled cyclization to build the challenging thermodynamically less stable 8R-hemiaminal moiety is also important in the synthesis of amathaspiramide D. The route is readily scalable, and gram quantity of the final product D has been prepared. [ABSTRACT FROM AUTHOR]

The aryl to vinyl palladium 1,4-migration was realized for the first time. The generated alkenyl palladium species was trapped by diboron reagents under Miyaura borylation conditions, providing a new method to synthesize ββ-disubstituted vinylboronates. The excellent regioselectivity and broad substrate scope were observed for this novel transformation. [ABSTRACT FROM AUTHOR]

The article describes a novel catalytic asymmetric approach for the highly enantioselective synthesis of chiral phthalides utilizing samarium diiodide protocol. The combination of chiral oxazolidinone and achiral amine serves an efficient catalyst system for the asymmetric reductive cyclization of a wide range of 2-acylarylcarbonylates. The method offers insights into the asymmetric reduction of carbonyl as well as the asymmetric protonation.

An efficient diastereoselective approach to access trans-5-hydroxy-6-alkynyl/alkenyl-2-piperidinones has been developed through nucleophilic addition of α-chiral aldimines using alkynyl/alkenyl Grignard reagents. The diastereoselectivity of alkenyl in C-6 position of 2-piperidinone was controlled by a-alkoxy substitution, while the alkynyl was controlled by the coordination of the a-alkoxy substitution and stereochemistry of sulfinamide. The utility of this straightforward cascade process is demonstrated by the asymmetric synthesis of the (-)-epiquinamide and (+)-swainsonine. [ABSTRACT FROM AUTHOR]

Two tunable arylative cyclizations of cyclohexadienone-containing 1,6-enynes are reported via rhodium(lll)- catalyzed C–H activation of O-substituted N-hydroxybenzamides. The use of different O substituents, i.e. O-Piv and O-Me, on the directing group allows the formation of either tetracyclic isoquinolones through an ©-Michael addition process or hydrobenzofurans through a ©-Michael addition process. Mechanistic investigations of these two cascade reactions clearly indicated that the C–H bond cleavage process was involved in the turnover-limiting step. Furthermore, the cyclization products could be subjected to various transformations for elaborating the pharmaceutically and synthetically valuable potential. This is the first example of a rhodium(III)-catalyzed arylative cyclization reaction of 1,6-enynes, and the results extend the application realm of Cp*RhIII-catalyzed C–H activation cascade reactions. [ABSTRACT FROM AUTHOR]

An organocatalytic cascade reaction was established for the construction of indoloquinolizidine derivatives bearing five contiguous stereo-centers from readily available aliphatic aldehydes, nitroethylenes, and tryptamine. This one-pot process gave 30-55% overall yields with excellent d.r. (>20:1 in all cases) and ee (91-98%). Additionally, quaternary stereogenic carbon center-containing indoloquinolizidines were prepared through NBS-mediated cyclization of one of the intermediates. [ABSTRACT FROM AUTHOR]

Huperzine A, huperzine B, and huperzine U are congeners isolated from the Chinese herb Huperzia serrata (=Lycopodium serratum) in minuscule amounts. The most efficient total synthesis of huperzine A, the first asymmetric total syntheses of huperzine B, and the first total synthesis of huperzine U have been achieved efficiently in overall yields of 17%, 1096, and 9%, respectively, each spanning 10-13 steps from (R)-pulegone. The featured steps include palladium-catalyzed Buchwald--Hartwig coupling and Heck cyclizatton reactions and an Ir-catalyzed olefin isomerization reaction. This work has established the absolute configurations of huperzine B and huperzine U and revealed that natural huperzine A, huperzine B, and huperzine U possess the same set of absolute stereochemistries, thus providing support for the potential role of huperzine B and huperzine U in the biosynthesis of huperzine A. [ABSTRACT FROM AUTHOR]

The asymmetric total synthesis of lagunamide A (3.0%, 20 steps longest linear sequence) and its five analogues, including the structure dehydrated at the C37 position, are detailed in this report. The key feature in this diverse synthesis includes the elaboration of four consecutive chiral centers at C37-40 and the final macrocyclization. Starting from chiral aldehyde 10, we synthesized both 1,3-anti and 1,3-syn homoallylic alcohols 20a and 20b through asymmetric aldol condensation and stereoselective allylation. The following esterification to introduce the l-N-Me-Ala unit resulted in significant epimerization. This problem was finally overcome by coupling the alcohols with the corresponding acid chloride of the l-alanine derivative. The key a,ß-unsaturated carboxylic acid unit was produced by cross-metathesis (CM) of methacrylaldehyde and related olefins. Interestingly, we found that the C7 configuration dramatically affected the ring closure. Natural lagunamide A (1a), its 39-epimer (1c), and its 2-epimer (1d) were obtained through macrolactamization between alanine and isoleucine moieties. [ABSTRACT FROM AUTHOR]

The first Cu-catalyzed asymmetric borylative cyclization of cyclohexadienone-containing 1,6-enynes is achieved through a tandem process: selective β-borylation of propargylic ether and subsequent conjugate addition to cyclohexadienone. The reaction proceeds with excellent regioselectivity and enantioselectivity to afford an optically pure cis-hydrobenzofuran framework bearing alkenylboronate and enone substructures. Furthermore, the resulting bicyclic products could be converted to bridged and tricyclic ring structures. This method extends the realm of Cu-catalyzed asymmetric tandem reactions using bis(pinacolato)diboron (B2pin2). [ABSTRACT FROM AUTHOR]

The zinc-mediated asymmetric allylation of chiral N-tert-butanesulfinyl aldimines with 3-bromomethyl-5H-furan-2-one proceeded in good anti/syn selectivities, providing optically pure substituted α-methylene-γ-butyrolactones bearing chiral amine with moderate to excellent yields (28-92%) and diastereoselectivities (76% to >99% de). [ABSTRACT FROM AUTHOR]

Non-C2-symmetric (N-alkyl, N-aryl)-hybrid chiral NHC/Cu(I) complex catalyzed asymmetric hydroboration of Nbenzoyl aldimines has been developed. The reaction proceeded smoothly at room temperature, giving α-amido boronic esters in excellent yields (up to 94%) and good enantioselectivities (up to 86% ee) [ABSTRACT FROM AUTHOR]

A complementary method for the preparation of 3,5-substituted pyrazoles in moderate to high yields has been explored via TfOH-induced addition of tosylhydrazones to the terminal alkynes. This acid-induced addition procedure might be an operationally safe alternative compared to typical 1,3-dipolar cycloaddition as there is no involvement of diazo compounds. [ABSTRACT FROM AUTHOR]

A samarium diiodide promoted tandem β-elimination/ cross-pinacol coupling was developed. A series of novel 1-vinyl- 1,2-diols with two adjacent quaternary carbon centers were obtained in moderate to good yields. Possible reaction pathways are proposed. [ABSTRACT FROM AUTHOR]

The enantioselective formal synthesis of (+)-englerin A and the total synthesis of (-)-orientalol F were successfully accomplished via a triene. The success enabled establishment of the relative as well as absolute stereochemistry of the organocatalytic [4+3]-cycloaddition reaction. [ABSTRACT FROM AUTHOR]

A highly enantioselective rhodium-catalyzed arylation of aliphatic N-tosylaldimines has been developed. The combination of chiral bicyclo[3.3.0]octadiene ligands, an active rhodium hydroxide complex, and neutral reaction conditions is the key to achieving high yield and enantioselectivity. The application of this method is demonstrated by the enantioselective synthesis of chiral 2-aryl pyrrolidines and piperidines in a one-pot procedure. Furthermore, excellent results are also obtained for the imine substrates with the more readily cleavable N-nosyl protecting group. [ABSTRACT FROM AUTHOR]

The first palladium−diene-catalyzed asymmetric Suzuki−Miyaura coupling reaction has been achieved. A number of functionalized biaryls were obtained in high yields and in moderate to high enantioselectivities. The existence of an ortho-formyl group greatly improves the catalyst efficiency and permits further synthetic elaborations. [ABSTRACT FROM AUTHOR]

An efficient one-pot asymmetric synthesis of highly substituted γ-lactams containing α-methylene groups has been successfully developed. A wide range of γ-lactams could be obtained in high yields with excellent diastereomeric ratios of up to 99:1 in favor of transisomers. In particular, excellent enantioselectivities of the two newly formed stereogenic centers with up to 99% ee were observed. [ABSTRACT FROM AUTHOR]

Monosubstituted C1-symmetric dicyclopentadienes as a new class of diene ligands have been developed for asymmetric arylation of N-tosylarylimines in excellent yields (98−99%) with high enantioselectivities (90−96%). The preparation of these diene ligands relied on an efficient lipase-catalyzed resolution as the key step. [ABSTRACT FROM AUTHOR]

Monosubstituted C1-symmetric dicyclopentadienes as a new class of diene ligands have been developed for asymmetric arylation of N-tosylarylimines in excellent yields (98−99%) with high enantioselectivities (90−96%). The preparation of these diene ligands relied on an efficient lipase-catalyzed resolution as the key step. [ABSTRACT FROM AUTHOR]

The first and asymmetric total synthesis of hedyosumins A, B, and C was accomplished in 13-14 steps from simple starting materials. The essential tools that allow us to access the tetracyclic skeleton include an organocatalytic [4 + 3] cycloaddition reaction, an intramolecular aldol condensation, and an intramolecular carboxymercuration/demercuration enabled lactonization. A CBS-catalyzed asymmetric reduction was employed to boost the ee of the synthetic natural products to an excellent level. This synthesis established the absolute configurations of hedyosumins A, B, and C. [ABSTRACT FROM AUTHOR]

A new and efficient sulfide monooxygenase-producing strain, ECU0066, was isolated and identified as a Rhodococcus sp. that could transform phenylmethyl sulfide (PMS) to (S)-sulfoxide with 99% enantiomeric excess via two steps of enantioselective oxidations. Its enzyme activity could be effectively induced by adding PMS or phenylmethyl sulfoxide (PMSO) directly to a rich medium at the early log phase (6 h) of fermentation, resulting in over 10-times-higher production of the enzyme. This bacterial strain also displayed fairly good activity and enantioselectivity toward seven other sulfides, indicating a good potential for practical application in asymmetric synthesis of chiral sulfoxides. [ABSTRACT FROM AUTHOR]

The first Rh−diene-catalyzed aqueous asymmetric 1,4-addition of α,β-unsaturated carbonyl compounds with arylboronic acids has been realized. By using a hydrophilic bicyclo[3.3.0] diene ligand, the reactions can be performed successfully in neat water at room temperature to afford the corresponding products in good yields and with very high enantioselectivities for both cyclic and linear substrates. [ABSTRACT FROM AUTHOR]

A highly practical and efficient asymmetric synthesis of chiral homoallylic amines by In-mediated allylation of chiral N-tert-butanesulfinyl imines in aqueous media at room temperature was developed. With 2-formylbenzoate imine substrates, the method allows the highly enantioselective achievement of a variety of pharmacologically important 3-allyl isoindolinone compounds. [ABSTRACT FROM AUTHOR]

An efficient and practical method for optical resolution of axially chiral biaryl dials using enantiomeric tert-butanesulfinamide as resolving agent was developed. The approach offers a very convenient and straightforward access to versatile enantiomerically pure C2-symmetric biaryl dials in good yields. With the obtained axially chiral dials, stereoselective synthesis of a series of cyclic trans-1,2-diols in optically pure form was investigated. [ABSTRACT FROM AUTHOR]

Glycoconjugates can be artificially synthesized by combinatorial biocatalysis. An example is given in this paper describing the construction of glycoconjugates array by using glycosidase and lipase in nonaqueous media. This array was started from glucose, with three aryl alcohols as the aglycone moiety of glycosides and five acids or esters as acyl donors for combinatorial acylation of glycosides, affording a three-dimensional array containing about 30 members with diverse structures. The array would be more abundant if more aglycones and acyl donors with other structures were filled in. Indeed, diverse classes of carbohydrates besides glucose can also be employed for generating diverse glycoconjugates due to their different roles in numerous physiological responses. The composition and distribution of the demonstration glycoconjugates array was detected and evaluated by HPLC-MS with electrospray ionization. And also, the distribution of the artificial array can be adjusted by changing the molar ratio of the auxiliary materials. [ABSTRACT FROM AUTHOR]

Develops a reaction system for the synthesis of chiral alpha,gamma-substituted gamma-butyrolactones. Examination of the asymmetric protonation of gamma-butyrolactone; Use of several chiral compounds as proton source; Construction of alpha-carbon chiral center; Configuration of trans product.