Collect. Czech. Chem. Commun. 1983, 48, 3474-3481

Bromination of 19-acetoxy-4β,5-cyclopropano-5β-cholestan-3-one

Jiří Joska, Jan Fajkoš and Jaroslav Zajíček

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


Bromination of the ketone II with Jacques' reagent afforded the dibromo ketone IV and the monobromo ketone V. On metal hydride reduction both bromo ketones gave the isomeric bromohydrins VIII, X, and XII the structures of which were established by standard reactions and by spectral evidence. Dehydrohalogenation of the bromo ketone V yielded the unsaturated ketone VII.