The relative degree of “syn-effect” for the γ-substituted vinylsulfones in their conversion to the corresponding allylsulfones with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) was determined by observing E/Z ratios of the resulting allylsulfones as follows: CH3O– ≥ AcO– > CH3– > –CH2– >> t-Bu– and Ph–.
通过观察所得烯丙基砜的 E/Z 比值,确定了 γ-取代的
乙烯基砜在与
1,8-二氮杂双环[5.4.0]十一-7-烯(
DBU)一起转化为相应的烯丙基砜时的 "协同效应 "相对程度如下:
CH3O- ≥ AcO- >
CH3- > -
CH2- >> t-Bu- 和 Ph-。