Synthesis of 4- O - d -Mannopyranosyl-α- d -glucopyranosides by Intramolecular Glycosylation of 6- O -Tethered Mannosyl Donors
作者:Gregor Lemanski、Thomas Ziegler
DOI:10.1016/s0040-4020(99)01053-4
日期:2000.1
A series of mannosyl donors linked via position 6 by a carbonate, oxalate, malonate, succinate, and phthalate tether, respectively, to position 3 of a glucoside and glucosamine acceptor afforded during intramolecularglycosylation, anomeric mixture of the corresponding disaccharides. The dependence of the diastereoselectivity on the glycosylation procedure, the solvent, and the blocking groups in comparison
Intramolecular glycosylation of prearranged glycosides part 5. α-(1→4)-Selective glucosylation of glucosides and glucosamines
作者:Thomas Ziegler、Axel Ritter、Jürgen Hürttlen
DOI:10.1016/s0040-4039(97)00729-6
日期:1997.5
The intramolecular (1 -->4) glucosylation of partially protected alkyl glucosides and glucosamines with phenyl 1-thioglucoside that is preconnected via its position 2 by a succinyl spacer to positions 3 of the glucosyl acceptor affords the alpha-linked disaccharides. The anomeric selectivity depends on the stereochemistry of the donor-acceptor-interaction and is not governed by neighboring group participation. In contrast, connecting the glucosyl donor by the succinyl bridge to position 6 of the glucosamine acceptor results in an alpha/beta-mixture of the corresponding disaccharides upon intramolecular glycosylation. (C) 1997 Elsevier Science Ltd.
Synthesis of benzyl α- and β-sophorosides, and of benzyl α-laminarabioside