Photochemische Reaktionen. 31. Mitteilung. [1]. Die photochemische Isomerisierung von C(‐10)‐diastereomeren 3‐Oxo‐Δ^1;5‐Steroiden

Abstract

Abstract The photochemical transformation of 3‐oxo‐17β‐acetoxy‐Δ 1;5 ‐androstadiene ( 2 ) and its 10α‐diastereoisomer 7 has been investigated. With low conversion of 2 , an isomer was produced for which structure 8 (6β‐H) is proposed. After longer photolysis times, both compounds, 2 and 8 , were consumed, and the four stereoisomeric photoproducts 9–12 were obtained. Products 9 and 10 on one hand, and 11 and 12 on the other, are photochemically interconvertible. Dienone 7 yielded a very similar product mixture from which ketones 10 and 12 could be isolated. Further, the presence of a dienone isomer was demonstrated to which structure 8 (6α‐H) is assigned.