Intramolecular hydrogen bonding in hydroxy-keto-steroids

Abstract

The i.r. spectra of hydroxy-keto-steroids with an equatorial-hydroxy-group α to the ketone show a band due to hydrogen bonding (OH ⋯ O type); those with an axial hydroxy-group α or β to the ketone exhibit two absorption bands, due to a free and a bonded hydroxy-group (OH ⋯π type). The mode of multiple hydrogen bonding in epimeric pairs of monohydroxy-diketo-steroids and dihydroxy-monoketo-steroids is discussed. Hydrogen bonding in dihydroxy-keto-steroids is more extensive than in monohydroxy-keto-steroids.