Synthesis of (±)-Dibenzocyclooctadiene Lignans, (±)-Schizandrin, (±)-Gomisin A and Their Stereoisomers, Utilizing the Samarium-Grignard Reaction

Abstract

Several (±)-dibenzocyclooctadiene lignans, (±)-schizandrin (1a) (±)-gomisin A (1b), and their stereoisomers 2a and 2b, were synthesized by the samarium-Grignard reaction of the phenylpropyl bromides 4 and the phenylacetone derivative 5 to give the erythro and threo-butanols 6 and 7 followed by oxidative aryl-aryl coupling reaction of each butanol.