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Conformation of ring A in some 2β-hydroxy- and 2β-acetoxy-Δ4-3-ketosteroids

✍ Scribed by K. Kuriyama; E. Kondo; K. Tori

Publisher
Elsevier Science
Year
1963
Tongue
French
Weight
282 KB
Volume
4
Category
Article
ISSN
0040-4039

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✦ Synopsis

DJERASSI, et al. (1) have pointed out that the optical rotatory dispersion (ORD) curve in substituted-A 4 -3-ketosteroids reflects conformational distortions in the B-ring rather than in the A-ring. Their conclusion is based on the observation that 17@-acetoxyandrost-4-en-3-one and its 2,2-dimethyl derivative have similar ORD curves, whereas its 6B-methyl derivative shows a completely different C"t-Ve. On the other hand, Johnson, et al. (2) have found out from their nuclear magnetic resonance (NMR) and ORD studies that the A-ring in 2B-acetoxycholestan-3-one is of a twist conformation, owing to a 1,3-diaxial interaction between the 2B-acetoxyl group and the 19-methyl group.

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