addition of propionate silylketene acelal 1 to 2-carbomethoxy cyclopentenone is promoted by bis(oxazoline)-Cu(II) complexes with high diastereoselectivity and good enantiomeric excesses. The absolute configuration of the product can be controlled by varying the copper counterion. A catalytic version of the reaction was developed, which gave ketoacid 5a in 72% d.e. and 63% e.e.
具有高非对映选择性和良好对映异构体过量的双(
恶唑啉)-Cu(II)配合物可促进
丙酸酯甲
硅烷基
乙烯酮缩醛1向2-羰基甲氧基
环戊烯酮的共轭加成反应。产物的绝对构型可以通过改变
铜抗衡离子来控制。开发了该反应的催化形式,得到72%de和63%ee的
酮酸5a