Highly   Enantioselective Construction of Strained Spiro[2,3]hexanes through a Michael   Addition/Ring Expansion/ Cyclization Cascade

Chuan-Gang Zhao,   Zhi-Tao Feng, Guo-Qiang Xu,* Ang Gao, Jing-Wei Chen, Zhu-Yin Wang, and   Peng-Fei Xu*

https://doi.org/10.1002/anie.201912834