of enolates can be formed stepwise from enolisable 1,3-dicarbonyl-substituted propene systems in the presence of catalytic amounts of 1,4-diazabicyclo[2.2.2]octane (DABCO) to accomplish a highly selective carbocyclization with beta,gamma-unsaturated alpha-keto esters, giving functionalized spiroketones with vicinal quaternary stereocenters.
可以在催化量的1,4-二氮杂
双环[2.2.2]辛烷(
DABCO)存在下,由可烯丙基的1,3-二羰基取代的
丙烯系统逐步形成两种类型的烯醇化物,从而实现具有β,γ的高选择性碳环化反应-不饱和的α-
酮酸酯,可得到具有邻近四元立体中心的功能化螺酮。