Synthetische Verwendung von Epoxynitronen. II. Synthese von Steroid‐α‐methyliden‐γ‐lactonen

Synthetic application of epoxynitrones. II. Syntheses of steroidal α‐methylidene‐γ‐lactones This communication describes the application of the epoxynitrone/CF3SO3SiR3 → 1,2‐oxazine annelation‐reaction [1] to the syntheses of steroidal α‐methylidene‐γ‐lactones from olefines, e.g. 12 → 14a/b → 16a/b → 18a/b → 20 → 22 (Scheme 2).