NEW PRODUCTS BY RING EXPANSIONS OF SOLID 17-HYDROXY-20-KETOSTEROIDS WITH GASEOUS HYDROCHLORIC-ACID

Gaseous hydrogen chloride reacts directly with crystalline 17-hydroxy- 20-ketosteroids like 17 alpha-hydroxy-progesterones (1, 5, 6, 8) to gi ve enlargement of ring D. In addition to the known acyloine rearrangem ent, new reaction types are observed which give rise to the products o f substitutive rearrangement with elimination of water. 16 beta-Chloro -(3) and 16 alpha-chloro-16 beta-methyl-17-oxo-D-homosteroids (7, 9) a re formed stereoselectively. The drying agent magnesium sulfate may ke ep the reaction products solid. Mechanistic proof is provided spectros copically (IR) and by the isolation of 17a beta-hydroxy-17a alpha-meth yl-D-homeandrost-4-ene-3,17-dione (2) and its conversion to 16 beta-ch loro-17a beta-methyl-D-homoandrost-4-ene-3,17-dione (3) with gaseous h ydrogen chloride. The new reaction types do not occur in solution.