A carbohydrate-based approach to the synthesis of polypropionate arrays (termed pyranosidic homologation) ultimately requires that the anomeric ( aldehydo) group be liberated and then reduced to CH 3. The bipyranose 4a has been examined in this context. Standard mercaptolysis reactions were ineffective due, in part, to the ease with which acid-catalyzed rearrangements occur. Even when the bicyclic system could be cleaved, hemiacetals [ e.g., 1,5-di- O-acetyl-3- O-benzyl-2-deoxy-4- C-methyl-2- C-( l- lyxo-2,3,4-triacetoxy-1-benzyloxybutyl)-α,β- l-arabinofuranose or 2- C-( d- threo-2-acetoxy-1-benzyloxybutyl)-3,4-di- O-benzyl-2-deoxy-4- C-methyl- l-xylopyranose ( 10b)] were resistant to mercaptolysis and were decomposed under the conditions for hydride reduction. The successful route developed in this report involved oxidation of 10b to a pyranolactone [ e.g., 2- C-( d- threo-2-acetoxy-1-benzyloxybutyl)-3,4-di- O-benzyl-2-deoxy-4- C-methyl- l-xylono-1,5-lactone], which yielded the N,N-dimethylamide. The latter was then reduced to an aldehyde, which in turn was deoxygenated by the Wolff-Kishner reaction, in modest yield.