David Rosenthal

Steroids—LXXVIII : The lead tetraacetate oxidation of a 5-hydroxy-B-norsteroid☆☆☆

Abstract The lead tetraacetate oxidation of the tertiary alcohol 1 gives rise to two products, 3a and 4a, which contain a transannular oxide bridge. These structures are determined by analytical and spectral properties and by two independent chemical interconversions. The stereochemistry can be deduced from these reactions. Two possible mechanisms for the formation of the products are presented.

The addition of nitrosyl fluoride to steroid 9(11)-olefins (1)

Abstract Nitrosyl fluoride was added to a series of steroid 9(11)-olefins to give, in moderate yield, the corresponding 11-nitrimino-9α-fluoro derivatives. The nitrimines could be hydrolyzed to the 11-ketones, or reduced by appropriate reagents to the corresponding 11-nitramines, 11-imines, and 11-amines. These reactions constitute a convenient and direct way to introduce fluorine into the 9α position of steroids. The scope and limitations of this reaction are discussed.