Reaction of dibenzalacetone with trimethyl phosphite and dimethylphosphorous acid

Abstract

1. Trimethyl phosphite reacts with dibenzalacetone to give 2, 2, 2-trimethoxy-3-phenyl-5-(β-phenyl)-vinyl-1,2-oxa-4-phospholene (II). 2. The phosphorane ring is opened at the P-O bond when (II) is hydrolyzed with water, with the formation of two keto phosphonates, probably the S-cis and S-trans conformers. 3. Phosphorane (II) reacts with dibenzalacetone by the diene synthesis scheme. © 1974 Consultants Bureau.