178. the use of aprotic solvents for nucleophilic substitution reactions at C(3) and C(17) in steroids

H. B. Henbest, W. R. Jackson

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Abstract

Cholestanes containing 3α-substituents (cyano, azido, bromo, fluoro, acetoxy) have been obtained in good yields (>70%) from reactions of cholestan-3β-yl toluene-9-sulphonate with nucleophiles in aprotic solvents. In comparison, reactions of cholestan-3α-yl toluene-p-sulphonate with cyanide and acetate ions gave more elimination, but the 3β-cyanide and 3β-acetate were obtained in 40% and 57% yields, respectively. Use of aprotic solvents inhibits structural rearrangement in nucleophilic replacement reactions at C(17), and good yields of 17α-azido-, -bromo-, -chloro-, and -fluoro-compounds were obtained from testosterone toluene-p-sulphonate. Reaction of this ester with acetate anion in N-methylpyrrolidone gave the 17α-acetate (34%) and 3-oxoandrosta-4,16- diene (57%).

Original languageEnglish
Pages (from-to)954-959
Number of pages6
JournalJournal of the Chemical Society (Resumed)
Publication statusPublished - 1 Dec 1962
Externally publishedYes

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