preferentially convert propargylic substrates, R1CCCR2R3X (X = Br, MeCO2, MeS(O)O or MeSO3) into allenes R3Sn(R1)CCCR2R3. Only when the group R1 causes much greater steric hindrance than with R2 and R3 is the acetylenic product R1CCCR2SnR3 formed. The stereochemical course of the allene formation has been studied in both the steroid and non-steroid series, and found to be mainly or exclusively
Stannylcopper(I)类,R 3的SnCu和[R 3的Sn] 2 CuLi,优先转换炔底物,R 1 CCCR 2 - [R 3 X(X = Br的,梅科2,
MES(O)O或内消旋3)转换成
丙二烯- [R 3的Sn(R 1)CCCR 2 - [R 3。只有当基团R 1倍的原因大得多的空间位阻比,其中R 2和R 3是炔乘积R 1 CCCR 2 SNR 3形成。已经在类
固醇和非类
固醇系列中研究了
丙二烯形成的立体
化学过程,并且发现其主要或仅具有抗性。