This book describes several new processes using bismuth(III) reagents and catalysts, with application to steroid chemistry. Two processes for the nucleophilic ring opening of epoxysteroids are presented: one describes the Ritter reaction to afford vic-N-acylamino-hydroxy compounds, whereas the other show that bismuth(III) salts can act both as nucleophiles and reaction promoters, to obtain ?-substituted-hydroxy steroids. The bismuth(III) salt-catalyzed rearrangement of epoxysteroids is described as a strategy to obtain steroids bearing abnormal ring fusions, inverted configuration at bridgehead stereocenters and methyl groups out of their typical positions, leading to olefinic 19-nor, 18,19-dinor- or 18-norsteroids. The bismuth(III) triflate-catalyzed cleavage of the C17-side chain of corticosteroid allows the easy preparation of highly functionalized 17-ketosteroids. Moreover, full structural elucidation of all the obtained compounds is provided and largely discussed. A general introduction provides the background knowledge to this work. The concept of pharmaceutical green chemistry is discussed in the light of its integration with chemical process within pharmaceutical chemistry.