NEW PREPARATION METHOD OF 5,7-PREGNADIENE-3,20-DIONE-DIETHYL KETAL

摘要

Disclosed is a preparation method of 5,7-pregnadiene-3,20-dione-diethyl ketal. The preparation method comprises: performing dehydration condensation on progesterone by using glycol to protect two carbonyls, so as to obtain a compound B; performing allylic selective oxidization on the compound B to obtain a compound D; performing condensation on the compound D and p-toluenesulfonhydrazide, so as to obtain a compound E; and performing a Shapiro reaction to remove hydrazone from the compound E, so as to obtain 5,7-pregnadiene-3,20-dione-diethyl ketal (a compound A).