trans-addition products formed in the hydrostannation of ethynes has been shown to proceed under the influence of organotin radicals. Attack of such radicals on the carbon-carbon double bond produces an ethyl radical containing two organotin groups. Elimination of one of the organotin moieties as a radical may result in the formation of the isomerized product. The course of the latter step is determined
主的异构化反式形成在
乙炔的hydrostannation -addition产品已经显示出
有机锡基团的影响下进行。这种自由基对碳-碳双键的攻击产生了包含两个
有机锡基团的乙基。消除
有机锡部分之一作为自由基可能导致异构化产物的形成。后面步骤的过程由几个因素决定。这些中的一种似乎是对于自由基中间体的那些构象的偏爱,其中相对于α-碳原子上的极性取代基,β-碳原子上的两个
锡原子都处于augche-位置。