Triethylamine → 20,20-Ethylenedioxy-3alpha-hydroxy-2alpha-methyl-5alpha-pregnane-11-one

Participants

Reaction Steps

A solution of chloroiridic acid (10 mg.) and trimethyl phosphite (1.5 ml.) in aqueous 90% isopropanol (20 ml.) was heated under reflux for 17 hours. The solution was then neutralised with triethylamine, 20,20-ethylenedioxy-2β-methyl-5α-pregnane-3,11-dione (0.66 g.) was added, and the mixture was heated under reflux for 48 hr. The reaction mixture was cooled and partitioned between methylene chloride and water. The organic layer was dried (MgSO4) and evaporated in vacuo. The residue (0.69 g.) was purified by preparative layer chromatography and crystallised from methyl acetate/petroleum ether (b.p. 60°-80°) to give 20,20-ethylenedioxy-3α-hydroxy-2α-methyl-5α-pregnan-11-one (0.42 g.), m.p. 167°-168°, [α]D + 68°.

Provenance & Evidence