Synthesis of steroids with nitrogen-containing substituents in ring D (Review)

Data published over the last 15 years on the chemical synthesis of biologically active steroids with nitrogen-containing substituents (mostly containing nitrogen heterocycles) in ring D are reviewed. Modern methods for the synthesis of nitrogen-containing derivatives from 17-keto steroids and 20-keto steroids and certain other methods for the synthesis of the target products are discussed. Concise data are also presented on three of the most important biological targets for nitrogen-containing steroids: enzymes 17α-hydroxylase-17/20-lyase (CYP17), aromatase (CYP19), and 24-sterol methyltransferase (SMT).