A new synthesis of L-ascorbic acid from D-galactose

Article abstract of DOI:10.1016/S0040-4020(01)88219-3

1,5-Anhydro-D-galactitol, easily available from D-galactose, was selectively protected in positions 2, 3 and 4 and converted into 5-O-acetyl-2,6-anhydro-3-deoxy-L-threo-hex-2-enonic acid methyl ester, which, on reaction with MCPBA in acetic acid gave 2,5-di-O-acetyl-α-L-lyxo-hex-2-ulopyranosonic acid methyl ester. Reaction of the latter with sodium methoxide produced sodium L-ascorbate in high yield. Several side-reactions and the conformations of some of the intermediates are also discussed.