Enantiomerically pure 2-alkenyl azetidines undergo a ring expansion into N-alkyl-1,2,3,6-azocines upon reaction with activated alkynes (ethyl propiolate or ethynyl p-tolyl sulfone). The scope of this ring enlargement, which provides a new entry to functionalized eight-membered ring nitrogen heterocycle, is discussed.
对映异构纯的 2-烯基氮杂
环丁烷在与活化的
炔烃(
丙炔酸乙酯或
乙炔基对甲苯基砜)反应后会发生扩环成 N-烷基-1,2,3,6-氮杂
环丁烷。讨论了这种环扩大的范围,它为功能化的八元环氮杂环提供了新的入口。