The Reductive Aromatization of Steroidal Dienones. A New Method for the Preparation of Estrone

Mechanisms of steroid oxidation by microorganisms. XIII. C22 acid intermediates in the degradation of the cholesterol side chain

“…The structure of Ilia was confirmed by partial synthesis (Scheme III). The bisnorchola-1,4-diene-3on-22-oic acid (X), obtained by refluxing IX with DDQ1 (Burn and Petrow, 1962), was aromatized by treatment with excess of radical anion derived from lithium metal and biphenyl in boiling tetrahydrofuran solution (Dryden et al, 1964). The product (Ilia)…”

Steroids

“…After selective protection of the C3-ketone, addition of the lithium compound (132) followed by an aqueous acid quench results in the chloro aldehyde (134). Treatment of (134) with potassium acetate and acetic anhydride forms the 16 -corticoid (137). Steroid (137) is a versatile intermediate for the synthesis of a variety of the aforementioned, potent glucocorticoids.…”

Steroidal estrogens

“…After hydrolysis estrone was obtained in 55% yield. The over-all yield of estrone was increased to 75% by the addition to the reaction mixture of a suitably acidic hydrocarbon (e.g., diphenylmethane, methylnaphthalene) which intercepts the by-product methyllithium and prevents its addition to the carbonyl group of the ketal CXXX (124,125). CXXXIII When 17 /3-acetoxy-1 a, 2a-oxido-5a-androstan-3-one (CXXXI) was treated with p-toluenesulfonic acid in acetic anhydride, the expected 2,170-diacetoxy-5aandrost-l-en-3-one (CXXXII) was isolated as a minor product.…”