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Reduction of fully protected 4,6-0-(4-methoxybenzylidene) hexopyranosides with sodium cyanoborohydride-trifluoroacetic acid in NN-dimethylformamide, or trimethylsilyl chloride in acetonitrile, gives the 6and 4 -0 -(4-methoxybenzyl) ethers, respectively, in good yield and good regioselectivity. The 4-methoxybenzyl ether linkage in products containing benzyl ethers or other protective groups is selectively cleaved upon treatment with cerium (iv) ammonium nitrate in aqueous acetonitrile.There is an increasing need for new protective groups and protective group strategies as the chemical syntheses of highly complex molecules evolve. Selectivity in introduction and removal under mild conditions in high yields are essential requirements.Recently the versatility of the 4-methoxybenzyl group for hydroxy-group protection was highlighted. ' 9 ' It was demonstrated that this group could be cleaved in a selective fashion using 2,3-dichloro-5,6-dicyanobenzoquinone in the presence of other protective groups, including benzyl ethers. We have recently shown that 4-methoxybenzyl 3,4,6-tri-O-acetyl-2deoxy-2-phthalimido-~-~-glucopyranoside could be cleaved with cerium(1v) ammonium nitrate (CAN) in acetonitrilewater (9 : 1) to give 3,4,6-tri-O-acetyl-Zdeoxy-2-phthalimido-~-D-glucopyranose in 88% yield.3 This procedure using CAN was, in our hands, found to give better yields than that with 2,3dichloro-5,6-dicyanobenzoquinone. In the present work the 4-methoxybenzyl ethers methyl 2,3-di-O-benzy1-6-0-(4-meth-

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