Über Steroide und Sexualhormone. 212. Mitteilung. Photochemische Umwandlungen von 20‐Keto‐pregnan‐Verbindungen

Abstract

Abstract It is shown that irradiation of the 20‐keto‐pregnane derivatives I, XI and XVI leads predominantly to cyclisation between the carbon atoms 18 and 20 with formation of the novel pentacyclic steroid compounds II, XII and XVII. Simultaneously fragmentation reactions occur yielding products of type XIX and XX.