An intramolecular cyclopropanation that involves cation intermediates rather than carbenes was developed. Three new C-C bonds (red) are created at a single carbon center derived from dichloromethane to give bicyclo[3.1.0]hexanes.

This work was carried out in the group of Prof. Philippe Renaud.

References:

• G. Xu, P. Renaud;
  "Intramolecular Cyclopropanation of 1,4-Dienes through Hydroboration-Homologation: Easy Access to Bicyclo[3.1.0]hexanes"
  Angew. Chem. Int. Ed., 2016, 55(11), 3657-3661; doi:10.1002/anie.201511100.