Regioselectivity in the reaction of β-vinyl-β-propiolactone with various nucleophiles was found to depend on the hard and soft acid and base (HSAB) principle. A hard base such as methoxide ion attacked the acyl carbon exclusively, while the nucleophilic attack of soft bases such as iodide and dialkyl cuprate preferred the terminal vinyl carbon to the β-carbon.
β-
乙烯基-β-
丙二酸内酯与各种亲核试剂的反应中,区域选择性被发现依赖于硬软酸碱(H
SAB)原则。硬碱如甲氧基离子专门攻击酰基碳,而软碱如
碘离子和双烷基
铜盐的亲核攻击则更倾向于攻击末端
乙烯基碳而非β碳。