Qian Yao, Han Yu, Hang Zhang, Shunxi Dong, Fenzhen Chang, Lili Lin, Xiaohua Liu and Xiaoming Feng
Chem. Commun., 2018,54, 3375-3378
DOI:
10.1039/C8CC01040D,
Communication
Here we report an efficient asymmetric [4+2] cycloaddition of β,γ-unsaturated α-ketoesters with cyclobutenones. The corresponding products were obtained in good yields (up to 92%) with excellent enantioselectivities (up to 98% ee) and diastereoselectivities (up to >19/1 dr). Moreover, based on the control experiments and previous reports, a possible catalytic cycle was proposed.
![Graphical abstract: Lewis acid catalyzed asymmetric [4+2] cycloaddition of cyclobutenones to synthesize α,β-unsaturated δ-lactones](/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=C8CC01040D "Graphical abstract")
