Kinetic and thermodynamic control in the formation of monoacetals from aldehydes and D-glucitol

Abstract

The formation under kinetic control of a 2,3-O-monoacetal in the reaction of an aldehyde with D-glucitol in acid solution, first shown to occur with n-butyraldehyde, has now been observed with both benzaldehyde and acetaldehyde. Hydrolysis of the 2,3-O-ethylidene acetal in aqueous acid gives substantial fission of the acetal ring followed by recombination to the 2,4-acetal. The 2,3-O-benzylidene acetal appears to undergo ring migration to the 2,4-acetal in anhydrous media.