Prearranged glycosides. Part 14: Intramolecular glycosylation of non-symmetrically tethered glycosides
摘要:
Partially benzylated 1-thio-beta -D-glucopyranosides were tethered via position 2 to position 3 of methyl alpha -D-glucopyranosyl and benzyl 2-phthalimido-2-deoxy-beta -D-glucopyranosyl derivatives, respectively, by non-symmetrical o-, m-, and p-methylbenzoate linkers. Intramolecular glycosylation of these prearranged glycosides lead to the corresponding non-symmetrically tethered alpha-(1-->4)-linked disaccharides as the exclusive or main products. The tethers were regioselectively opened by transesterification affording isomeric disaccharide accepters which are susceptible for further elongation of the sugar chain at positions 3 and 2', respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.
Prearranged glycosides. Part 14: Intramolecular glycosylation of non-symmetrically tethered glycosides
摘要:
Partially benzylated 1-thio-beta -D-glucopyranosides were tethered via position 2 to position 3 of methyl alpha -D-glucopyranosyl and benzyl 2-phthalimido-2-deoxy-beta -D-glucopyranosyl derivatives, respectively, by non-symmetrical o-, m-, and p-methylbenzoate linkers. Intramolecular glycosylation of these prearranged glycosides lead to the corresponding non-symmetrically tethered alpha-(1-->4)-linked disaccharides as the exclusive or main products. The tethers were regioselectively opened by transesterification affording isomeric disaccharide accepters which are susceptible for further elongation of the sugar chain at positions 3 and 2', respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.