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.
提供了前体化合物,用于合成11-硫属族取代类固醇和去甲类固醇,特别是18-、19-和A-去甲类固醇。这些化合物是无环或取代的多烯,具有正确的几何构型,以在环化时提供自然的环融合。为了启动环化,硫属原子与双键的位置关系使得在硫属原子质子化时,所得到的碳阳离子将与双键相互作用,形成π键(如果环化引发剂是碳环)或σ键(如果环化引发剂是无环)。在环化后,发现所得到的类固醇的C-11位的取代基处于α位。提供了各种生产环化前体的方法。