The selective oxidation of trimethylsilylated D-galactose diethyl dithioace
tal using Collins reagent provided the corresponding D-galacto-hexodialdo d
ithioacetal. Successive acid hydrolysis, isopropylidenation, and cleavage o
f the dithio acetal group gave the 1,2;3,4-di-O-isopropylidene-L-galacto-he
xodialdo-1,5-pyranose as a key intermediate for the synthesis of 6-fluoro-
and 6-deutero-substituted L-fucose derivatives.