A NOVEL 1,3 0-]C SILYL REARRANGEMENT IN CARBOHYDRATE-CHEMISTRY - SYNTHESIS OF ALPHA-D-GLYCOPYRANOSYLTRIMETHYLSILANES

Reductive lithiation of 2-O-trimethylsilyl derivatives of phenyl thiogluco and -galactopyranosides gives rise to a 13 O→C silyl migration leading to α-D-gluco and -galctopyranosyltrimethylsilanes in good yields. The expected β-elimination is observed to a small extent in the case of a 23-di-O-trimethylsilyl derivative of phenyl thioglucopyranoside where a tandem 13 O→C 14 O→O silyl rearrangement occurs but becomes the only possible reaction in the case of an O-silylated derivative of phenyl thiomannopyranoside. © 1990.