To clarify the utility as a protective group of 3-O-allyl group on ring-opening polymerization of alpha-D-glucopyranose 1,2,4-orthopivalate derivatives, four orthopivalate derivatives, 3-0-allyl-6-O-pivaloyl- (1), 3-O-allyl-6-O-benzyl- (2), 3,6-di-O-allyl-(3), and 3-O-allyl-6-O-methyl-alpha-D-glucopyranose 1,2,4-orthopivalates (4), were selected as starting monomers and were polymerized under -30 degreesC in CH2O2 using BF3.Et2O as a catalyst. All the orthopivalate derivatives 1-4 were found to give stereoregular polysaccharides, (1-->4)-beta-D-glueopyranans. Thus, it was concluded that the allyl group as a protective group at 3-O position of glucose othropivalate is acceptable to yield stereoregular (1-->4)-beta-D-glueopyranans, cellulose derivatives.