The thermal [2+2]cycloaddition products of 1-chloro-(II) and 1-bromo-2-(9-fluorenylidene)ethylene (X) were found to be two head-to-tail dimers, fluorene-9-spiro-1′-[2′-chloro-3′-(9-fluorenylidene)-4′-chloromethylene]cyclobutane (VI) and its bromo-analog (XI) respectively.
1-
氯-(II)和1-
溴-2-(9-
芴基亚甲基)
乙烯(X)的热[2+2]环加成产物被发现为两个头尾相接的二聚体,分别为
芴-9-螺-1′-[2′-
氯-3′-(9-
芴基亚甲基)-4′-
氯亚甲基]
环丁烷(VI)及其
溴类似物(XI)。