Reactions of carbonyl compounds with tervalent phosphorus reagents. Part 11. A re-examination of the reaction of benzaldehyde with phosphorus trichloride in the presence of acetic anhydride

Abstract

The reaction of equimolar amounts of benzaldehyde, phosphorus trichloride, and acetic anhydride has been shown to involve successive formation of benzylidene diacetate (4) and α-chlorobenzyl acetate (5). By an Arbusov reaction, the latter is converted into the dimer (3), previously recognised as the precursor of α-hydroxybenzylphosphonic acid (1a), the known product of an aqueous work-up. A simple preparation of α-chlorobenzyl acetate (5) is described.