Zhi-Qin Liang, Liang Yi, Kun-Quan Chen, Song Ye*

The bifunctional N-heterocyclic carbene catalyzed [3 + 4] annulation of enals and 5-alkenyl thiazolones was developed, giving the corresponding thiazole-fused e-lactones in high yields with excellent diastereoselectivties and enantioselectivities. The thiazole-fused e-lactone could be isomerized to the spirocyclic thiazolone-cyclopentanone without erosion of enantioselectivity.

This work has been published in J. Org. Chem., 2016, 81 (11), 4841–4846.