Synthese der 2,5‐Diole des A‐nor‐5α‐Cholestans und A‐nor‐5β‐Cholestans

Abstract

Treatment of A‐nor‐Δ3(5)‐cholestene‐2‐one (1) with alkaline hydrogen peroxide gave 3β,5‐epoxy‐A‐nor‐cholestane‐2‐one (2) and the epoxylactone 3 (BAEYER‐VILLIGER reaction). LiAlH4‐reduction of 2 yielded A‐nor‐5β‐cholestane‐2β,5‐diol(4) (main product) and A‐nor‐5β‐cholestane‐2α,5‐diol (5). LiAlH4‐reduction of 1 led mainly to A‐nor‐Δ3(5)‐cholestene‐2α‐ol (8). Catalytic hydrogenation of 8 gave the known A‐nor‐5α‐cholestane‐2α‐01 (10), A‐nor‐5β‐cholestane‐2α‐01 (11) (main product), A‐nor‐5β‐cholestane (9) and A‐nor‐5β‐cholestane‐2‐one (12). By LiAlH4‐reduction of the ketones 12 and 13 the two additional alcohols 14 and 15 were obtained.

Synthesis, Structure, and Reactivity of Secosteroids Containing a Medium‐Sized Ring. Part 36. Transannular photocyclization of some unsaturated 5,10‐secosteroidal ketones: A reevaluation

“…e.g. [7] [S]), and noticed that all of them were in a narrow range of 4.4 f 0.5 ppm, comparable to those observed for the oxetane 2 (3.95 ppm), and none at a field as high as for 5 and 7 (3.05 and 3.07 ppm, resp.). These last two values are, however, perfectly in accordance to the chemical-shifts values of oxirane protons.…”