Studies on the Constituents of the Seeds of Hernandia ovigera L. VIII. Syntheses of (±)-Desoxypodophyllotoxin and (±)-β-Peltatin-A Methyl Ether

Abstract

(±)-Desoxypodophyllotoxin (2), a chief component of the seeds of Hernandia ovigera L., and (±)-β-peltatin-A methyl ether (3), an analogous phenyltetralin lignan, which have 2, 3-trans, 3, 4-cis configuration were synthesized according to the method developed for the synthesis of hernandin (1). The syntheses were pursued using the corresponding 4-phenyl-1, 2-dihydronaphthalene lactones (9 and 10) followed by cleavage of the lactone moiety to give the unsaturated hydroxy acids (11 and 12). Subsequent hydrogenation and ring closure by means of p-toluenesulfonic acid afforded both 2, 3-trans, 3, 4-cis and 2, 3-cis, 3, 4-cis ligans (2 and 13 or 3 and 14), which were isolated by preparative thin layer chromatography.