Collect. Czech. Chem. Commun. 1998, 63, 1543-1548

Epalons: Synthesis of 3α,7α-Dihydroxy-5α-pregnan-20-one

Hana Chodounská and Alexander Kasal

Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 166 10 Prague 6, Czech Republic


3α,7α-Dihydroxy-5α-pregnan-20-one (12) was prepared from (20R)-pregn-5-ene-3β,20-diyl 3-acetate 20-benzoate (1). ∆5-Olefin was oxidized in an allylic position and hydrogenated. Inversion of a configuration at carbon C-3 was carried out by solvolysis in N,N-dimethylformamide of 3β-tosylate in the presence of sodium nitrite. For stereoselective reduction of the 7-oxo group, L-Selectride® was used.

Keywords: Steroids; Epalon; GABAA-Modulator; 7α-Hydroxylase; Solvolysis; L-Selectride®; 3α,5α-Tetrahydroprogesterone.