2-Phosphorylation of D-Erythorbic Acid

Abstract

D-Erythorbate 2-phosphate (3) was prepared by phos phorylation of 5, 6-0-isopropylidene-D-erythorbate (5) with phosphoryl chloride at high pH in the presence of pyridine. Following removal of the 5, 6-acetal, a crude magnesium salt of 3 was isolated in 67–71% yield. The salt contained 74% of 3, 9% of D-erythorbate 2-diphosphate (7), and 5% of bis-(D-erythorbyl) 2, 2′-phosphate (6). Analytically pure 3 was obtained as its crystalline magnesium and tricyclohexyl-ammonium salts in 26 and 47% yields, respectively, from 5.