摘要 |
<p>A method of making 1α-hydroxy-2-methylene-19-norhomopregnacalciferol. The method includes the steps of condensing a bicyclic ketone with an allylic phosphine oxide to produce a protected 19-norpregnacalciferol analog, thereafter cleaving the protecting group to form 22-alcohol, converting the alcohol to an ester, reducing the ester to 17β-isopropyl-19-nor-vitamin D analog, and finally deprotecting the 17β-isopropyl derivative to form the desired compound.</p> |