Synthesis of 2,5,6- and 3,5,6-tri-O-methyl-D-galactose

Starting from methyl β-D-galactofuranoside, 3,5,6-tri-O-methyl-D-galactose (9) and 2,5,6-tri-O-methyl-D-galactose (16) were synthesized. The alditol acetates were prepared from 9 and 16, and their behavior in g.l.c. was compared. Mass spectra of the alditol acetates from 9 and 16 showed that these compounds gave fragmentations as expected. The alditol acetate from 16 was also prepared by an alternative route.