The first diastereoselective syntheses of the natural acetal glucosides, (2R)-2-beta-D-glucopyranosyloxy-4-hydroxy-2H-1,4- benzoxazin-3(4H)-one and (2R)-2-beta-D-glucopyranosyloxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one, are described by reaction of 0-(2,3,4,6-tetra-0-acetyl-beta-D-glucopyranosyl) trichloroacetimidate with hemiacetalic aglucones of the 2-hydroxy-2H-1,4-benzoxazin-3(4H)-one skeleton.