The readily accessible 2, 3, 5-tri-O-benzyl-~-arabinofuranose (I) was converted successively to 40-benzoyl-2, 3, 5-tri-O-benzyl-~-arabinose diethyl dithioacetal (111) and 40-benzoyl-2, 3, 5-tri-O-benzyl-~-arabinose dibenzyl acetal (VI). Replacement of the benzoyl group in the latter compound by methyl, followed by hydrogenolysis of the five benzyl groups, afforded crystalline 4-O-methyl-@-D-arabinopyranose (IX). This synthesis may be regarded as ...