Stereoselective opening of ring E in furostan sapogenins. An efficient route to 16,22R,26-hydroxy steroids

Abstract

The growing importance of side chain hydroxylated steroids as biogenetic precursors and biologically active substances (e.g. acdysones, antheridiol, steroid alkaloids, intermediate products in the mode of action of vitamin D) encouraged us to search a route to such compounds starting from 26-hydroxy-furostan sapogenins, which may be prepared in a simple reaction from the corresponding readily available spirostan compounds. The present communication reports the stereoselective opening of ring E in furostan sapogenins which leads to substances that are of use for the aforesaid synthesis.