1,3-Dipolar cycloaddition of nitrile oxides to 17 beta -hydroxy-17 alpha -vinyl steroids of the estrone series proceeds both regio- and stereoselectively. The stereoselectivity of the process decreases in going to steroids of the androstane series. The major epimer has S configuration of the new chiral center.
1,3-Dipolar cycloaddition of nitrile oxides to 17 beta -hydroxy-17 alpha -vinyl steroids of the estrone series proceeds both regio- and stereoselectively. The stereoselectivity of the process decreases in going to steroids of the androstane series. The major epimer has S configuration of the new chiral center.