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Tiffeneau ring enlargement of 17-keto steroids

Tiffeneau ring enlargement is a route to D-homosteroids. Goldberg and Monnier treated the 17i5-hydroxy-20-amine (91) prepared by hydrogenation of 17a-cyano-5a-androstane-3)3,17j5-diol (90a) with nitrous acid and obtained 3i5-hydroxy-5a-D-homo-androstan-17a-one (92). [Pg.386]

This method has been successfully used to prepare 3-methoxy-D-homo-estra-1,3,5(10)-trien-17a-one (96), 17al5-hydroxy-D-homo-androst-4-en-3-one (97a) and 17a/ -hydroxy-D-homo-estr-4-en-3-one (97bT  [Pg.387]

Goldberg and Wydler have shown that the 17a-ketone is not the only product of the Tiffeneau ring enlargement sequence. Careful examination of the products derived from nitrous acid deamination of 17a-aminomethyl-5a-androstane-3/l,17j6-diol 3-acetate (91) showed the presence of a minor amount of isomeric D-homo-17-one (98). [Pg.387]

With 3a-hydroxy-5a-androstane-ll,17-dione acetate (99) a mixture of 17a- (101) and 17-D-homo ketones (102) is obtained in a 1 to 6 ratio. [Pg.387]

Wendler, Taub and Slates have established that the course of rearrangement is independent of the configuration of the 17-aminomethyl group.  [Pg.387]


See other pages where Tiffeneau ring enlargement of 17-keto steroids is mentioned: [Pg.386]    [Pg.201]   


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