1,1,2-Trihalocyclopropanes (halogen = chlorine or bromine) undergo 1,2-dehalogenation on reaction with methyl lithium, and in a number of cases the product is a 1-halocyclopropene. In the reactions of (20, X = Br, Cl) and (25) a rearrangement occurs even at low temperatures and propargylic halides are isolated, while (16) is converted to 2-chlorocyclohex-2-enylidene which may be trapped by furan.
1,1,2-三卤代
环丙烷(卤素=
氯或
溴)在与
甲基锂反应时会进行1,2-
脱卤作用,在许多情况下,产物是1-卤代环
丙烯。在(20,X = Br,Cl)和(25)的反应中,即使在低温下也会发生重排,并分离出炔丙基卤,而(16)转化为2-
氯环己-2-
烯基,可能被
呋喃捕获。