place of the methyl ether used previously, is a judicious choice by which to obtain steroids possessing an aromatic A-ring with a 2-OH substituent. Finally, the vinyl groups of the synthesized fluoro and hydroxy steroids have been oxidized by the Wacker process in good yields. An X-ray crystal structure of the fluoro steroid 14b, the trans-anti-trans ring configuration of which matches those in natural
5-氟-1-碘苯并环丁烯 (7) 和 5-叔丁氧基-1-碘苯并环丁烯 (8) 已用于合成标题化合物。该策略涉及使用邻二甲苯的分子内 Diels-Alder 环加成作为关键步骤。我们已经表明,在合成开始时引入叔丁基醚作为保护基团,代替之前使用的甲基醚,是获得具有芳香族 A 环和 2 -OH 取代基。最后,合成的氟和羟基类固醇的乙烯基已被瓦克法以良好的产率氧化。报道了氟类固醇 14b 的 X 射线晶体结构,其反式-反-反式环构型与天然产物中的构型相匹配。