Buchner ring expansion

Buchner ring expansion
Named after Eduard Buchner
Reaction type Rearrangement reaction

The Buchner ring expansion is a two-step organic C-C bond forming reaction used to access 7-membered rings. The first step involves formation of a carbene from ethyl diazoacetate, which cyclopropanates an aromatic ring. The ring expansion occurs in the second step, with an electrocyclic reaction opening the cyclopropane ring to form the 7-membered ring.

The Buchner Ring Expansion
The Buchner Ring Expansion