The Contraction and Expansion of Steroid Rings

The Contraction and Expansion of Steroid Rii. — The four rings are considered in turn additional reactions of this type will be found under Epoxide Rearrangements (p. 365). 

Apparently contradictory results in the Tiffeneau-Demjanov expansion of ring have been only partially clarified from separate study of the epimeric 3-aminomethyl-3-ols (491) derived from 5a-cholestan-3-one, 17j5-hydroxy-5a-androstan-3-one, and the related trans-2-decalyl derivatives. The three reported products, the A-homo-3-one (492), A-homo-4-one (493), and the oxiran (494), are formed in differing proportions (Table 3). The same products arise from reaction between the 3-oxo-steroids and diazomethane it is clear from 

Compound 5(X-Cholestane series Reagent Oxiran (494) homo- 3-Ketone (492) A-homo-4-Ketone (493) Ratio (3-CO)/ (4-CO) Ref. 

3-Ketone 1 ip-Hydroxy-5x-androstane series Sa-CHiNHz (ax). CH2N2 10 40—50 ca. 0.2 394 

3-Ketone trans-Decalin series 2-CH2NH2 (ax), CH2N2 very little 44 31 1.4 273 

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