Abstract
Benzoylation of the enediol system of L-ascorbic acid and 5, 6-isopropylidene-L-ascorbic acid have been investigated with the aim of obtaining O-benzoyl derivatives of L-ascorbic acid stabilized against oxidation. 2-O-benzoyl-L-ascorbic acid, 3-O-benzoyl-5, 6-isopropylidene-L-ascorbic acid, 2, 6-di-O-benzoyl-L-ascorbic acid, 3, 6-di-O-benzoyl-L-ascorbic acid and 3, 5, 6-tri-O-benzoyl-L-ascorbic acid have been prepared by making choice of suitable reaction conditions, especially of the mole ratios of the three reagents i.e.L-ascorbic acid or its isopropylidene homologues, benzoyl chloride and base. The structure of the products were determined on the basis of elementary analyses. IR and NMR data supplemented by UV spectra and PK values.
