On the reactivity of 23-methoxycarbonyl furospirostanes.

Authors :: Macías-Alonso M
Flores-Álamo M
Iglesias-Arteaga MA
Source :: Steroids [Steroids] 2011 Sep-Oct; Vol. 76 (10-11), pp. 1021-31. Date of Electronic Publication: 2011 Apr 14.
Publication Year :: 2011
Abstract: Brønsted and Lewis acid-catalysed reactions of the 23-methoxycarbonyl furospirostanic side chain are described. While bromination, deuteration and BF(3)·Et(2)O/AcOH treatment involve regioselective F-ring opening with exclusive participation of Δ(22)-furostenic intermediates, BF(3)·Et(2)O/Ac(2)O treatment leads to irreversible E- or F-ring cleavage.<br /> (Copyright © 2011 Elsevier Inc. All rights reserved.)