THE PREPARATION OF 4,6-<i>O</i>-BENZYLIDENE-<scp>D</scp>-GLUCAL AND THE REACTION OF METHYLLITHIUM WITH METHYL 2,3-ANHYDRO-4,6-<i>O</i>-BENZYLIDENE-α-<scp>D</scp>-ALLOPYRANOSIDE

Abstract

4,6-O-Benzylidene-D-glucal has been prepared by the reaction of benzaldehyde with D-glucal. The reaction of commercial methyllithium with methyl 2,3-anhydro-4,6-O-benzylidene-α-D-allopyranoside produces the C 2 -methylated 1,2-unsaturated compound 4,6-O-benzylidene-1,2-didehydro-1,2-dideoxy-2-methyl-D-ribo-hexopyranose. Their structures have been proven by first-order analyses of their nuclear magnetic resonance spectra.