Photochemische Reaktionen. 31. Mitteilung. [1]. Die photochemische Isomerisierung von C(-10)-diastereomeren 3-Oxo-Δ1;5-Steroiden



The photochemical transformation of 3-oxo-17β-acetoxy-Δ1;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.