Asymmetric tandem Michael addition-Wittig reaction to cyclohexenone annulation.

A highly stereoselective tandem Michael addition-Wittig reaction of (3-carboxy-2-oxopropylidene)triphenylphosphorane and alpha,beta-unsaturated aldehydes has been developed by employing the combined catalysis of a newly designed bulky chiral secondary amine 1g, LiClO(4), and DABCO. The multifunctional 6-carboxycyclohex-2-en-1-ones were generally obtained in excellent diastereo- and enantioselectivities (dr up to >50:1, 86-99% ee).