申请人:The Board of Trustees of Leland Stanford Junior University
公开号:US04032579A1
公开(公告)日:1977-06-28
Precursor compounds are provided for use in the synthesis of 11-chalcogensubstituted steroids and nor-steroids, particularly 18-, 19- and A-nor-steroids. The compounds are acyclic or substituted polyenine with the olefinic groups having the proper geometry to provide the natural ring fusions upon cyclization. To initiate cyclization, a chalcogen atom is positioned in relation to a double bond, so that on protonation of the chalcogen atom, the resulting carbocation will interact with the double bond to form a pi bond if the cyclization initiator is carbocyclic and a sigma bond if the cyclization initiator is acyclic. Upon cyclization, it is found that the substituent at C-11 of the resulting steroid is in the alpha position. Various methods are provided for producing the cyclization precursor.
提供了用于合成11-硫、硒、碲替代类固醇和非类固醇的前体化合物,特别是18-、19-和A-非类固醇。这些化合物是无环或取代的聚烯烃,其中烯基基团具有适当的几何构型,以在环化反应中提供天然的环融合。为了启动环化反应,硫、硒或碲原子被定位在双键旁,以便在硫、硒或碲原子质子化时,所得的碳阳离子将与双键相互作用,从而形成π键(如果环化引发剂是碳环的话)或σ键(如果环化引发剂是无环的话)。在环化反应中,发现所得类固醇的C-11位的取代基处于α位。提供了多种方法来制备环化的前体。