New Synthetic Methods and Reagents for Complex Carbohydrates. VII. Syntheses and Glycosylation Reactions of Glycopyranosyl Dimethylphosphinothioate Series Having a Nonparticipating Group at the C-2 Position

Abstract

Abstract Several glycopyranosyl dimethylphosphinothioates having a nonparticipating group at the C-2 position could be easily prepared by reactions of the corresponding glycopyranose and dimethylphosphinothioyl chloride using butyllithium as a base in tetrahydrofuran. These dimethylphosphinothioates are stable at room temperature and gave the corresponding α-glycosides, predominantly in good yields, by reactions with alcohols using silver perchlorate as an activator in the presence of molecular seives 4A in benzene at room temperature. Also, the combined use of iodine and a catalytic amount of triphenylmethyl perchlorate was effective for this glycosidation as a new activating system instead of silver perchlorate. Further, the synthetic intermediates of H-disaccharide and the Lewis X antigen were prepared using the present method.