21- A resioselective process for preparing 21-chloro steroids

摘要

PCl _5, PCl _3, POCl ₃ or SO ₂ Cl ₂ and already use imidazole, or PPh _3, and CCl ₄ provides a method of dehydrating an 11-hydroxy steroid with Reggio optional. The described method from 11α- or 11β- hydroxy steroid △ ^9,11 steroids are selectively formed in a 11,21- dihydroxy steroid 21-chloro-be used in the one step conversion of a △ ^9,11 steroid have. In addition to the method for the selective conversion of Reggio 11β- chloro steroid △ ^9,11 steroids and method of switching a 11,17,21- trihydroxy-21-chloro steroid -11,17- dihydroxy steroid of and technology.