19-Nor-Δ4-3-oxosteroid (IX) was synthesized starting from 3α, 5α-cyclo-6β, 19-oxidosteroid (I) through 3β-substituted-Δ5-steroid-19-oic acid (VII), whose synthesis was achieved by the three methods : i) Hydrolysis of 3β-hydroxy-Δ5-steroid-19-oic acid 3, 19-lactone (VI) which was prepared by oxidizing either 3β, 19-dihydroxy-Δ5-steroid (III) or 3β-hydroxy-19-oxo-Δ5-steroid (V) with Jones reagent or Oppenauer reaction, ii) Oxidation of 3β, 19-dihydroxy-Δ5-steroid 3-acetate (III) with the excess Jones reagent, iii) Reduction of 3α, 5α-cyclo-6-oxo-19-oic acid (IV) with sodium borohydride and subsequent acid-catalysed solvolysis of a mixture of resultant 6-epimeric hydroxy acids (XIII and XIV) in a suitable solvent. 3β-Substituted-Δ5-steroid-19-oic acid (VII) was in turn converted to 19-nor-Δ4-3-oxosteroid (IX) in two ways : i) Oxidation of 3β-hydroxy compound and subsequent acid-treatment of the resultant Δ5-3- oxosteroid-19-oic acid (VIII), ii) Pyrolysis of the 3β-acetoxy-Δ5-steroid-19-oic acid (VII) to afford 3β-acetoxy-Δ5 (10)-steroid (XI), followed by alkaline hydrolysis, Jones oxidation, and acid-treatment, successively.
