Water → HCID 12851163, compound

Participants

Reaction Steps

To a solution of 2.4 g of lead diacetate-trihydrate in 180 ml of dimethylformamide and 24 ml of acetic anhydride was added 4.6 g of (20S)-20-methylpregn-5-ene-1α,3β,21-triol. After standing at room temperature for 24 hr., the mixture was poured onto 1 kg of a 3:1 water--ice mixture and then extracted with ether. The ether extract was washed with water, dried (Na2SO4) and evaporated by means of a water aspirator. The residue was chromatographed on 100 g of silica gel. Elution with 1:1 hexane--ether afforded 1.14 g (20%) of (20S)-3β,21-diacetyloxy-20-methylpregn-5-en-1α-ol, mp 148°-149°. Elution with ether gave first 0.24 g (4.6%) of (20S)-3β-acetyloxy-20-methylpregn-5-ene-1α,21-diol, mp 202°-203° and then 2.94 g (57%) of (20S)-21-acetyloxy-20-methylpregn-5-ene-1α,3β -diol, mp 121°-121°. Finally, elution with ethyl acetate afforded 0.79 g (17%) of starting triol.

Provenance & Evidence