6,19-carbon-bridged steroids. Synthesis of 6,19-methanoprogesterone.
نویسندگان
چکیده
6,19-Methanoprogesterone (4) was synthesized in nine steps from the readily available 3 beta,20 beta-diacetyloxy-5 alpha-bromo-6,19-oxidopregnane (5) in 14% overall yield. The additional carbon atom was introduced by reaction of a C-19 aldehyde with Ph3PCHOCH3 under salt free conditions and subsequent hydrolysis to give the homologous aldehyde. Intramolecular addition of the newly incorporated carbonyl (C-19a) to the olefinic C-6 in ring B was achieved by means of a Prins reaction with TiCl4 as Lewis acid.
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عنوان ژورنال:
- Organic & biomolecular chemistry
دوره 1 6 شماره
صفحات -
تاریخ انتشار 2003