ChemInform Abstract: Synthesis, Structure, and Reactivity of Secosteroids Containing a Medium‐Sized Ring. Part 36. Transannular Photocyclization of Some Unsaturated 5,10‐Secosteroidal Ketones: A Reevaluation.

Abstract

Synthesis, Structure, and Reactivity of Secosteroids Containing a Medium-Sized Ring. Part 36. Transannular Photocyclization of Some Unsaturated 5,10-Secosteroidal Ketones: A Reevaluation.-The structures of (III) (space group P21 with Z = 2) and its benzoate are determined by X-ray and NMR analysis. On the basis of obtained results, (IIa) is proposed as revised structure of (IVa), earlier reported to be the single irradiation product of (Ia), whereas (IIb) instead of (IVb) is now reported to be the minor irradiation product of (Ib). A mechanism for the formation of the newly postulated structures is discussed. -(HECKENDORN, R.; FUHRER, H.; KALVODA, J.; LORENC, L.; PAVLOVIC, V.; MIHAILOVIC, M. L.; Helv.