A new synthesis of β,γ-unsaturated esters from three components, aldehydes, chloromethyl p-tolyl sulfoxide, and tert-butyl acetate, via magnesium carbenoid 1,2-CH and 1,2-CC insertion as the key reaction
作者:Tsuyoshi Satoh、Hironori Yamashita、Jun Musashi
DOI:10.1016/j.tetlet.2007.08.039
日期:2007.10
aromatic aldehydes, carbenoid 1,2-CH insertion reaction took place from the magnesium carbenoids to afford β,γ-unsaturated butyric esters having a substituent at the β-position. On the contrary, when the adducts were derived from electron-rich aromatic aldehydes, carbenoid 1,2-CC insertion reaction took place from the magnesium carbenoids to give β,γ-unsaturated butyric esters having the aromatic group
衍生自各种醛的1-氯乙烯基对甲苯基亚砜与叔烯醇锂的加成反应在-78°C中的乙酸丁酯在THF中的收率高。镁类化合物是通过格氏试剂通过亚砜-镁交换反应处理这些加合物而生成的。当加合物衍生自烷基醛或电子不足的芳族醛时,类胡萝卜素从类镁镁发生1,2-CH插入反应,得到在β-位具有取代基的β,γ-不饱和丁酸酯。相反,当加合物衍生自富含电子的芳族醛时,类胡萝卜素镁发生了类胡萝卜素1,2-CC插入反应,从而生成了在γ位具有芳族基团的β,γ-不饱和丁酸酯。在后面的反应中观察到高度立体定向的1,2-CC插入反应。这个程序为合成β提供了一个很好的方法,