α-(Methoxycarbonyl)benzylidene quasi-phosphonium ylides, which are unreactive toward most carbonyl compounds, are found to undergo the Wittig reaction upon irradiation; irradiation with acyclic carbonyl compounds, e.g. benzaldehydes and acetophenones, afford the corresponding alkenes, whereas the reaction with cyclohexanone affords 1-phenyl-1-(methoxycarbonyl)hepta-1, 2-diene.
α-(甲氧羰基)苄叉次膦叶立德对大多数羰基化合物不反应,但在光照下可进行Wittig反应;无环羰基化合物(如
苯甲醛和
苯乙酮)的光照反应得到相应的烯烃,而
环己酮的反应得到1-苯基-1-(甲氧羰基)
庚-1,2-二烯。