Studies on the Preparation of Bioactive Lignans by Oxidative Coupling Reaction. III. Synthesis of Polyphenolic Benzofuran and Coumestan Derivatives by Oxidative Coupling Reaction of Methyl (E)-3-(4-Hydroxy-2-methoxyphenyl) propenoate and Their Inhibitory Effect on Lipid Peroxidation.

Three dihydrobenzofuran derivatives 11, 19, 22, a Pummerer's ketone 20 and a dimeric phenylpropanoid 24 were synthesized by oxidative coupling reaction of methyl (E)-3-(4-hydroxy-2-methoxyphenyl)propenoate 10, which was prepared from umbelliferone. The major product 11 was converted into its acetate 21 and schizotenuin D analogs 27, 28, 29. A new coumestan derivative 13 was synthesized from 29. Ten synthetic compounds thus obtained were tested for inhibitory effects on lipid peroxidation in rat brain homogenate.