Substituted benzaldehydes and acetophenone preferentially attack the γ position of gem-dichloro allyl anion, but show a significantly increased α-selectivity if 12-crown-4 is present. This behaviour is discussed on the basis of theoretical computations.
取代的
苯甲醛和
苯乙酮会优先攻击宝石-二
氯烯丙基阴离子的γ位置,但是如果存在12-crown-4,则显示出显着提高的α-选择性。在理论计算的基础上讨论了这种行为。