Differentiation of keto groups in the Michael adducts of levoglucosenone with cyclohexanone

Resumo

The keto group in the carbohydrate residue of diastereoisomeric Michael adducts of levoglucosenone and cyclohexanone is more reactive than that in the cyclohexanone fragment. The adducts have been converted to the corresponding ethylene, trimethylene, and dimethyl ketals, tosylhydrazones, oxiranes, and Wittig methylenation products with complete or high regioselectivity.