Synthetic Studies on Lignans and Related Compounds. VII. : Synthesis of β-Apoplicatitoxin Trimethyl Ether

Abstract

β-Apoplicatitoxin trimethyl ether (8) was synthesized by selective photocyclization of a dibenzylidenebutyrolactone (6). The photocyclization was preliminarily examined in various solvents by use of a model compound (1), and the total yield of resulting isomeric β-apolignans (2a and 2b) and the ratio of 2a/2b were shown to increase with increasing solvent polarity.