REACTION OF 2,3-ANHYDR0-4,6-O-BENZYLIDENE-α-D-HEXOPYRANOSIDES WITH PROPENYLMAGNESIUM CHLORIDES. REGIOSELECTIVE CARBON CHAIN EXTENSION AT THE C-2 POSITION OF HEXOPYRANOSIDES
The reaction of methyl 2,3-anhydro-4,6-O-benzylidene-α-D-allopyranoside (l) with ethylmagnesium bromode in the presence of CuI afforded 4,6-O-benzylidene-1,2-dideoxy-D-rlbo-hex-1-enopyranoside (2), Similarly, methyl 2,3-anhydro-4,6-O-benzylidene-α-D-gulopyranoside (6) gave 4,6-O-benzylidene-1,2-dideoxy-D-xylo-hex-1-enopyranoside (7).