Cx. Guo et Pl. Fuchs, CEPHALOSTATIN SUPPORT STUDIES 12 - THE FIRST SYNTHESIS OF THE AGLYCONE OF THE POTENT ANTITUMOR STEROIDAL SAPONIN OSW-1, Tetrahedron letters, 39(10), 1998, pp. 1099-1102
The protected aglycone (21e-beta) of the potent anti-tumor agent OSW-1
(1) was synthesized in 9 steps from 5-androsten-3 beta-ol-17-one (10)
in 55% overall yield. Key reactions involve ene installation of the s
ide chain, regio and stereoselective dihydroxylation and diastereosele
ctive reduction of the C16 ketone. (C) 1998 Elsevier Science Ltd. All
rights reserved.