An efficient approach to partially O-methylated α-D-mannopyranosides using bis-tert-butyldiphenylsilyl ethers as intermediates
作者:MaSelma Arias-Pérez、MaJesús Santos
DOI:10.1016/0040-4020(96)00600-x
日期:1996.8
Differential migratoryaptitudes of secondary tert-butyldiphenylsilyl (TBDPS) groups have been observed for the bis-silylated derivatives of methyl and allyl α-D-mannopyranosides under several basic media. A remarkable variation of the selectivity in the migration of the TBDPS group at position 3 (O-3 → O-2 versus O-3 → O-4) was found by changing the hardness of the base and reaction conditions. This
title compounds were obtained by condensation of d -glucono-, d -galactono-, or l - glycero - d - gluco -heptono-1,5-lactones with methyl 2,3-di- O -(trimethylsilyl)-α- d -mannopyranosides having various substituents on C-4 and C-6, in the presence of trimethylsilyl trifluoromethanesulfonate as the catalyst. Except for a 6-acetoxyl group on a lactone component and a ( tert -butyldiphenylsiloxy) group