C-13 NMR-SPECTRA OF 2-FUNCTIONALIZED DELTA(4)-3-KETO STEROIDS - CARBON-1 AND CARBON-19 PROBES FOR CONFORMATIONAL PREFERENCE

Abstract

The C-13 NMR spectra of 2-substituted 4-en-3-one steroids have been studied. The functional groups include 2-alpha- and 2-beta-substituted 3-thia-butanoate or 4-thia-pentanoate moieties. The analysis mainly reflects on the gamma-interactions of gauche nature and syn-diaxial interactions. A simple protocol for the conformational analyis on ring A of these steroids has been postulated based upon the resonances of carbon-1 and carbon-19.