The addition of cyclohexyl and t-butyl free radicals to silylated derivatives of alkyl 2-(1-hydroxyalkyl) propenoates was found to be stereoselective . In the case of the cyclohexyl radical the stereoselectivity was dependent upon the conditions used to generate the free radical and to quench the intermediate. Stereoselectivity in additions of the t-butyl radical was found to be temperature-dependent. In all cases stereoselectivity increased as the steric bulk of the group attached to the carbinol oxygen increased. A simple model which accounts for the stereoselectivity is proposed.
研究发现,环己基和叔丁基自由基与 2-(1-羟基烷基)丙烯酸烷基硅烷化衍生物的加成具有立体选择性。环己基自由基的立体选择性取决于生成自由基和淬灭中间体的条件。研究发现,t-丁基自由基加成的立体选择性与温度有关。在所有情况下,立体选择性都会随着连接到羰基氧上的基团立体体积的增加而增加。提出了一个解释立体选择性的简单模型。