Regioselective Intermolecular [2 + 2]-Cycloaddition of α‑Iodo-Unsaturated Ketones Promoted by Diisobutylaluminum Hydride

The development of intermolecular [2 + 2]-cycloaddition of α-iodo-unsaturated ketones in the presence of diisobutylaluminum hydride (Dibal-H) is reported to produce various trispirocyclic derivatives containing a cyclobutane ring. This sequential lactonization/[2 + 2]-cycloaddition proceeds in high regioselectivity under mild conditions.据报道，α-碘代不饱和酮在二异丁基氢化铝（diisobutylaluminum hydride, Dibal-H）存在下可发生分子间[2+2]环加成反应，生成多种含环丁烷环的三螺环衍生物。该串联内酯化/[2+2]环加成过程在温和条件下展现出优异的区域选择性。