Stereoselective synthesis of pentacyclic steroids functionalized at C-11

We set out to describe an efficient and versatile method for preparing pentacyclic steroids diversely substituted at C-11 from cholic acid, via a stereoselective epoxidation and the epoxide opening as the key steps. The characteristic 1H and 13C NMR spectroscopic features of the synthesized compounds are reported.

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► A stereoselective synthesis of pentacyclic steroids is described.
► The key step is a stereoselective epoxide-opening lactonization.
► Various substituents can be introduced at the C-11 position of the steroidal skeleton.