Treatment of some O-benzyl-protected aldopyranoses and aldofuranoses with sodium 2-propoxide or K2CO3 brought about their equilibration and the loss of the elements of benzyl alcohol, with concomitant formation of a Z aldehyde. The latter rearranged rapidly in solution to the corresponding E lactol.
ANASTASIA, MARIO;ALLEVI, PIETRO;CIUFFREDA, PIERANGELA;FIECCHI, ALBERTO;SC+, J. ORG. CHEM., 56,(1991) N, C. 3054-3058