Stereospecific annulation of cyclic alkenes for the preparation of cis-fused seven-membered ring systems was accomplished by sequential [2 + 2] cycloaddition, exo-allylation, hydrohalogenation, and free radical ring expansion. The new strategy extends our recently developed cyclobutanone-based ring expansion reactions.
通过顺序的[2 + 2]环加成,外烯丙基化,氢卤化和自由基环扩环,可以完成用于制备顺式稠合七元环系统的环状烯烃的立体特异性环氧化。新策略扩展了我们最近开发的基于
环丁酮的环扩环反应。