Showing papers on "Koenigs–Knorr reaction published in 1990"
TL;DR: This mild «one-pot» procedure gives O-glycosides in excellent yields with high stereochemical control, even with unreactive and hindered glycosyl acceptors.
Abstract: A one-step conversion of thioglycosides into 1,2-trans- or 1,2-cis-O-glycosides was accomplished, in situ, by treatment with bromine in the presence of a glycosyl acceptor and a promoter such as silver triflate or mercuric cyanide. This mild «one-pot» procedure gives O-glycosides in excellent yields with high stereochemical control, even with unreactive and hindered glycosyl acceptors. The reaction conditions are compatible with various protecting groups such as acetates, benzoates, benzyl ethers, N-phthalimido groups, and benzylidene acetals
123 citations
TL;DR: In this paper, it was shown that, with fully acetylated glycosyl halides as a donor, in silver trifluoromethanesulfonate-promoted couplings, O-acetylation of the nucleophile occurs as a side reaction.
29 citations
TL;DR: Chloroacetylation of alkyl glycopyranosides of β-D-galactose, glucose, mannose, and xylose, using chloroacetic anhydride as acylating reagent, gave the corresponding fully chlorocatylated pyranose derivatives in excellent yields.
22 citations
TL;DR: In this paper, the 13.2-O-GA29β-D-glucopyranoside (1e) and 13.1-OGA29 β-Dglocopyr-anoside(1h) were synthesized from GA29 methyl ester and confirmed by 1H NMR and GC-MS.
10 citations
TL;DR: Glycosyl esters constitute a widespread family of natural products such as anti-tumor agents, antibiotics, terpenoid glycosides, plant pigments4 and other substances.
7 citations