Issue 5, 1970

Synthetic steroids. Part XI. Stereochemistry of the Tiffeneau—Demjanov ring expansion of 5α-cholestan-3-one

Abstract

The reaction of 5α-cholestan-3-one with acetone cyanohydrin has been shown to give a mixture of epimers (II and III; R = H) containing at least 80% of the epimer with the axial cyano-group. Each of these cyanohydrins has been converted into its acetate and then, by reduction, into the corresponding amino-alcohol, both of which have been deaminated with nitrous acid. Epimer (II; R = H) gives as the sole product of rearrangement the A-homo-ketone (VI), whereas the epimer (III; R = H) furnishes the same ketone (VI) along with an exocyclic epoxide by-product (X). Each of the intermediate amino-alcohols (IV and VII; R = NH2) has been synthesised independently from the appropriate epoxide (IX or X) and the stereochemistry of the deamination reactions is discussed.

Article information

Article type
Paper

J. Chem. Soc. C, 1970, 736-738

Synthetic steroids. Part XI. Stereochemistry of the Tiffeneau—Demjanov ring expansion of 5α-cholestan-3-one

J. D. Ballantine, J. P. Ritchie and P. J. Sykes, J. Chem. Soc. C, 1970, 736 DOI: 10.1039/J39700000736

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