Showing papers in "Tetrahedron in 1981"

TL;DR: A variety of methods for the conversion of α,β-unsaturated aldehydes to the corresponding acids have been explored as mentioned in this paper, and the best approach uses sodium chlorite and gives the desired transformation.

TL;DR: In this article, two highly stereocontrolled syntheses of the optically active form of the aliphatic segment 2 of rifamycin S were described and compared.

TL;DR: Trimethylsilyl triflate is a powerful silylating agent for organic compounds and acts as a catalyst which accelerates a variety of nucleophilic reactions in aprotic media as discussed by the authors.

TL;DR: In this paper, the conformational properties of medium and large-ring organic molecules have profound consequences on the stereochemical course of their chemical reactions, and the diastereomeric composition of the products was determined.

TL;DR: The electrophilic reactivity of arenes coordinated to the chromium tricarbonyl unit has been developed into several distinct methods for coupling carbon nucleophiles with aromatic rings as mentioned in this paper.

TL;DR: In this paper, Li enolates of hindered aryl esters condense with aldehydes to give predominantly threo aldols, with a ratio of 6.5:1.

TL;DR: In this article, a photo-thermal olefin metathesis of cheap, abundantly available Diels-Alder adducts of 1,3 cyclopentadienes and p-benzoquinones was proposed.

TL;DR: Palladium catalyzed reactions of arenediazonium salts for arylation of aliphatic and cyclic olefins and allylic alcohols, styrene and ethyl acrylate were studied.

TL;DR: In this paper, an electron transfer from samarium to halides and hydrogen abstraction from THF is discussed. But the mechanism of this reaction is not discussed, except for the electron transfer in the presence of a proton donor.

TL;DR: In this paper, a number of organoselenium reagents are introduced as efficient initiators of ring closures leading from unsaturated substrates to lactones, cyclic ethers and cyclic thioethers.

TL;DR: The marine sponges Dysidea herbacea, D. chlorea and Phyllospongia foliascens were differentiated with difficulty in the field as mentioned in this paper.

TL;DR: In this paper, various highly stereoselective asymmetric reactions based on chiral diamines having pyrrolidine ring are described, and some of these reactions have been successfully applied to the syntheses of natural products.

TL;DR: In this paper, conditions for metalation of a variety of cyclic vinyl ethers and reaction of the resulting carbanions with electrophiles are described, and effects of the vinyl ether structure on the relative rates of metalation are discussed.

TL;DR: In this paper, an efficient method for the regioselective enhancement of the nucleophilicity of polyhydroxy compounds has been developed, based on partial stannylation of carbohydrate with (Bu3Su)2O and subsequent electrophilic attack with benzoyl chloride.

TL;DR: In this paper, Polyazacycloalkan-Nessigsauren with 12−18 ringgliedern und mil Alkylverzweigung dargestellt und ihr Komplexbildungsverhalten in Abhangigkeit von der unterschiedlichen Konformation der Donoratome untersucht.

TL;DR: The use of acylnitroso compounds of the general formula RCONO as enophiles in the formation of carbon-nitrogen bonds is described in this paper, where both inter- and intramolecular ene reactions have been studied.

TL;DR: In this paper, N-Benzyloxycarbonyl amino-protecting group (Z) was removed by using HBr-AcOH, which was then removed by removing the benzyloxy carbonyl peptide group by HBrAcOH.

TL;DR: In this paper, a yeast reduction of ethyl acetoacetatc and 6-methyl-5-hepten-2-ol was used to obtain 87% optical purity in a 5-step sequence in 73% overall yield.

TL;DR: In this paper, a synthesis of (2 S,3 S,7 S )-3,7-dimethylpentadecan-2-yl acetate (2 ) and propionate ( 3 ) is described.