17,21-Bis(acetyloxy)pregn-4-ene-3,20-dione → 17,21-Diacetoxy-6-methylene-4-pregnene-3,20-dione

Participants

Reaction Steps

A suspension of 1.0 g of sodium acetate in 30 ml of methylene chloride, 30 ml of formaldehyde dimethylacetal and 3.8 ml of phosphorus oxychloride is combined with 1.0 g of 17,21-diacetoxy-4-pregnene-3,20-dione and refluxed for 35 hours under agitation. After cooling to room temperature, the mixture is diluted with methylene chloride and water. Under stirring, a saturated soda solution is added dropwise until an alkaline reaction of the aqueous phase has been obtained. The organic phase is separated, washed with water, dried over sodium sulfate, and evaporated under vacuum. Finally, the product is recrystallized from acetone/hexane, thus isolating 825 mg of 17,21-diacetoxy-6-methylene-4-pregnene-3,20-dione, mp 227°-228° C.

Provenance & Evidence