Method of synthesizing 1 alpha-hydroxy-2-methylene-19-nor- vitamin D compounds

摘要

A method of making 1alpha-hydroxy-2-methylene-19-norhomopregnacalciferol is described. The method includes the steps of condensing a bicyclic ketone with an allylic phosphine oxide to produce a protected 19-norpregnacalciferol analogue, thereafter cleaving the protecting group to form 22-alcohol, converting the alcohol to an ester, reducing the ester to 17beta-isopropyl-19-nor-vitamin D analogue, and finally deprotecting the 17beta-isopropyl derivative to form the desired compound.