The order of first bond formation in the intramolecular photocycloaddition of 2-(4′-pentenyl)-cyclohex-2-enones
作者:Nizar Haddad、Nitsa Galili
DOI:10.1016/s0040-4039(97)01373-7
日期:1997.8
Complete trapping of 1,4-diradical intermediates, formed in the photocycloaddition of 9, provide direct evidence that first bond formation takes place at either C(α) or C(β) positions of the cyclic enone. No cleavage of the 1,4-diradical 10 or endo-diradical intermediates 11 and 12 could be detected. However, partial cleavage of the exo-diradical intermediates 13 and 14 was measured. Unusual long-range
在9的光环加成反应中形成的1,4-双自由基中间体的完全捕获提供了直接的证据,表明第一键的形成发生在环状烯酮的C(α)或C(β)位置。没有检测到1,4-二自由基10或内二自由基中间体11和12的裂解。然而,测量了外双基中间体13和14的部分裂解。以与环丙基羰基自由基重排的竞争速率获得了不寻常的远程芳族自由基取代。