iodine (I2) afforded 2,5-dihydrofurans while that of readily available 1-aryl or 1-methyl substituted 2,3-allenols with bromine (Br2), N-bromosuccinimide (NBS), I2 or N-iodosuccinimide (NIS) formed the not easily available but synthetically useful 3-halo-3-alkenals and 2-halo-2-alkenyl ketones with good selectivity and yields via a sequential electrophilic interaction of X+ with the allene moiety, 1,2-aryl
伯2,3-
烯丙醇与
碘(I 2)的反应可制得
2,5-二氢呋喃,易得的1-芳基或1-甲基取代的2,3-
烯丙醇与
溴(Br 2),N-
溴代琥珀
酰亚胺(
NBS),I 2或N-
碘代琥珀
酰亚胺(NIS)形成了不易获得但合成有用的3-卤代3-烯醛和2-卤代-2-烯基酮,具有良好的选择性,并通过X +与N的顺序亲电相互作用获得了良好的收率
丙二烯部分,1,2-芳基或1,2-质子移位和H +消除过程。