Studies on the Constituents of the Seeds of Hernandia ovigera L. V. Syntheses of Epipodophyllotoxin and Podophyllotoxin from Desoxypodophyllotoxin

Abstract

Epipodophyllotoxin (EPT) and podophyllotoxin (PT) were prepared from desoxypodophyl-lotoxin (DPT), obtained from the seeds of Hernandia ovigera L. (Hernandiaceae). EPT was obtained together with dehydrodesoxypodophyllotoxin (I) by a radical bromination of DPT with N-bromosuccinimide (NBS) followed by hydrolysis of the resultant 1-bromo-DPT, which was confirmed to be a mixture of la- and lβ-bromo compounds (7:3). EPT was oxidized with pyridinium chlorochromate to give podophyllotoxone (IV). The stereoselective reduction of IV to afford PT was examined with a variety of reagents, and borane-tert-butylamine complex was found to be effective. © 1986, The Pharmaceutical Society of Japan. All rights reserved.