Asymmetric Domino Reaction of α,β-Unsaturated Aldehydes and α-Acyl α,β-Unsaturated Cyclic Ketones Catalyzed by Diphenylprolinol Silyl Ether.

Abstract

An asymmetric domino reaction combining vinylogous Michael reaction, hydration of aldehyde, and oxy-Michael reaction proceeds with α,β-unsaturated aldehydes and α-acyl α,β-unsaturated cyclic ketones in the presence of diphenylprolinol silyl ether to afford tetrahydrochromane derivatives with excellent enantioselectivity. After the domino reaction, addition of Wittig reagent and acid in the same reaction vessel promoted a second domino reaction incorporating retro oxy-Michael reaction, isomerization, and Wittig reaction to afford chiral functionalized cyclic 1,3-diene derivatives with excellent enantioselectivity. Overall, six reaction steps proceed in a one-pot procedure.