For the synthesis of 4-Deoxy-4-methylvoglibose, intramolecular 1, 3-dipolarcyclo addtion of nitrone 111 and 121 was examined.
Our proposed synthetic scheme includes the regioselective epoxide opening of epoxy alcohol 96 and nitrone formation from alcohol 109 and 119. Regioselective epoxide opening of 96 was attempted using organocopper reagent. Alcohol 109 and 119 were readily obtained from alcohol 104 via oxidation, Methylenation and desilylation in sequence. Alcohol 109 and 119 were subjected to Swern oxidation followed by nitrone formation with N-benzylhydroxylamine.
Finally, intramolecular 1,3-dipolar cycloadditions were intended. Formation of crucial intermediates oxazolidine 112 and 122 could not be attained.