Showing papers in "Tetrahedron Letters in 1985"

TL;DR: The preparation of the thiolsulphonate derivatives 3 and 7 of L-cysteine and glutathione, respectively, via their corresponding S-nitroso derivatives 2 and 6, is described.

TL;DR: The structure of the chromophore of an antitumor antibiotic neocarzinostatin has been elucidated as a bicycro[7,3,0]dodecadiyne system having naphthalenecarboxylic acid, aminosugar and ethylene carbonate units as mentioned in this paper.

TL;DR: Based on the intermediates revealed by 13C-NMR spectroscopy, the mechanism of levulinic acid formation in acid catalysed hydrolysis of 2-hydroxymethylfurane (1) and 5-hexyl carbaldehyde (2-carbaldehyde) is proposed in this paper.

TL;DR: In this article, conjugated dienoates, dienones and dienals are obtained with high stereospecificity (⩾95%) and in high yields from the corresponding (E,E) and (Z) vinylic halides, and substrates (methyl acrylate, methyl vinyl ketone or acrolein).

TL;DR: In situ trapping of reaction intermediates combined with stereochemical studies of the reaction of lithium dimethylcuprate with enones provides evidence for a pathway involving d,π-cuprate-enone and copper(III) β-adducts as important intermediates in cuprate-mediated conjugate addition of carbon.

TL;DR: In this article, organocuprates and chlorotrimethylsilane are compatible as separate species in THF or ether solution at −50 to −78°, and in combination can both accelerate and improve 1,4-addition reactions with conjugated carbonyl compounds.

TL;DR: It is shown that iminopentitols have considerable potential as glycosidase inhibitors, and was found to be identical to an alkaloid recently isolated from Angylocalyx boutiqueanus.

TL;DR: In this paper, a very efficient method to transform β-ketosulfoxides into optically active epoxides is described, which is based on the reduction of β-hydroxysulfoxide with DIBAL or DIBal/ZnCl 2.

TL;DR: In this paper, a working mechanistic hypothesis is proposed which rationalizes the stereochemical outcome of the synthesis of substituted bicyclo[3.3.O]octenones, using dicobaltoctacarbonyl mediated alkene-alkyne cyclizations.

TL;DR: In this paper, the reactions of oxazolidone with N-benzylimines proceed with exceptional levels of asymmetric induction to form the cycloadducts, and subsequent dissolving metal reduction affords the homochiral β-lactam derivatives in good overall yield.

TL;DR: The anomeric hydroxyl group of various furanose and pyranose hemiacetals can be replaced by a fluorine atom stereoselectively, conveniently, mildly, and on gram-scale using DAST in THF at room temperature.

TL;DR: It is conclusively proved by this chemical synthesis that lipid A is the active principle of bacterial endotoxin.

TL;DR: In this article, the reaction of benzene solutions of arylacetylenes with 1 equiv of chloroacetone and 2 equiv. of Et3N, using a mixture of (PPh3)4 Pd and CuJ as catalyst, affords 1,4-diaryl-butadiynes in very good yields.

TL;DR: The isolation and structure elucidation of rebeccamycin 1, a new antitumor agent from , is described and the NMR spectra of 1 and its peracetate 2 are discussed.

TL;DR: Ketones can be homologated to α,gb-unsaturated esters or amides via their enol triflates by a palladium-catalyzed reaction with carbon monoxide and alcohols or amines.

TL;DR: In this article, a 22-membered macrolide has been isolated from a Red Sea sponge and the structure of the tetraformate has been determined on basis of spectral data using 2D-NMR correlations.

TL;DR: In this article, a bicyclic dipeptide derivative with fixed conformation simulating that of the two central amino acid residues in type II′ β-turn has been synthesized starting from L-glutamic acid and L-cysteine in short steps.

TL;DR: In this paper, a primary alcohol can be protected as a highly stable p-anisyl ether, which undergoes mild oxidative deprotection by ceric ammonium nitrate.

TL;DR: PdCl2(CH3CN)2 catalyzes the hydrolysis of dioxolane acetals and ketals in moist CH3CN, while in acetoze, efficient and more reproducible exchange reactions take place as mentioned in this paper.

TL;DR: The structure of nigellicine (1), an unusual alkaloid from the seeds of Nigella sativa, was determined by x-ray diffraction and spectroscopic techniques as mentioned in this paper.

TL;DR: An organometallic reagent prepared from CH 2 I 2, Zn, and TiCl 4 was used for methylenation of the title ketones as discussed by the authors, which was shown to be effective.

TL;DR: In this paper, the electrocarboxylation of a large variety of organic halides is achieved in simple and mild conditions in diaphragm-less cells, and the results are shown to be stable.

TL;DR: Aldehydes undergo preferential allylation in the presence of ketones by the tin or zinc mediated method, easily effected in aqueous media as discussed by the authors, and they can be easily allylated by a metal-oxide mixture.

TL;DR: In this paper, the reaction of vinyl cyclopentanes having two electron-withdrawing groups with α,β-unsaturated esters or ketones in the presence of Pd 2 (dba) 3.

TL;DR: In this paper, Diethylamino-sulfur trifluoride (DAST) has been found to react with the free anomeric hydroxyl of suitably protected aldoses and ketoses to afford glycosyl fluorides.

TL;DR: Indole was converted into several 2-substituted derivatives by using carbon dioxide both for N-protection and to give an intermediate carbanion stabilizing group.

TL;DR: In the presence of anhydrous cerium(III) chloride, Grignard reagents react with Ketones to afford addition products in high yields, even though the substrates are susceptible to abnormal reactions with GRIGNARD reagents alone.

TL;DR: In this article, the acrylate of commercial D-pantolactone was added to cyclopentadiene, isoprene and butadiene with high diastereofacial selectivity.

TL;DR: The t-Butyloxycarbonyl (BOC) group on indoles and pyrroles can be removed cleanly and in high yield by simple thermolysis as mentioned in this paper.

TL;DR: The chemical structure of E. coli lipid A was elucidated to be 2 by determination of the nature of the individual acyl groups bound to the two hydroxyl groups in positions 3,3′ and the two amino groups of the D-glucosamine disaccharide phosphate backbone.