Regioselective Control in the Oxidative Cleavage of 4,6-O-Benzylidene Acetals of Glycopyranosides by Dimethyldioxirane
摘要:
The oxidative cleavage of 4,6-O-benzylidene acetals of glycopyranosides using dimethyldioxirane (DMDO) leads to the corresponding hydroxy-benzoates lent yields. With a Proper choice of the neighboring protecting groups, this oxidative fragmentation provides the 6- or 4-hydroxyl derivatives in a highly regioselective manner.
Regioselective Oxidative Cleavage of Benzylidene Acetals of Glycopyranosides with Periodic Acid Catalyzed by Tetrabutylammonium Bromide
作者:Jean-Michel Vatèle
DOI:10.1055/s-0033-1340056
日期:——
A combination of periodic acid, tetrabutylammonium bromide, and wet alumina in dichloromethane efficiently oxidized benzylideneacetals of carbohydrates to the corresponding hydroxybenzoates in excellent yields (>90%). Under these conditions, other protecting groups, such as tert-butyl(dimethyl)silyl, tert-butyl(diphenyl)silyl, and functional groups, such as epoxide, were unaffected. By varying the