1,2-Wittig rearrangement

The 1,2- Wittig rearrangement is a name reaction in organic chemistry. She was found by Nobel Prize winner Georg Wittig and named after him. In the Wittig rearrangement ethereal radical migrates to a deprotonated ether.

The intermediate product of this reaction is an alkoxy lithium salt and the final product is an alcohol. With a good leaving group and the electron -withdrawing group such as a cyanide in the anionic carbon atom it is cleaved and the corresponding ketone is formed.

Reaction mechanism

To the input of the reaction of the ether is an anion is generated by deprotonation with a strong base. By cleavage of the ether linkage results in a Ketylanion radical and an alkyl radical. The alkyl now migrates to the ketyl radical recombination and forms under the new connection.

The alkyl group moves in the order of their thermodynamic stability of the radicals methyl < primary alkyl < secondary alkyl < tertiary alkyl. The radical Ketylanionradikal pair is very short-lived and are located in a solvent cage, but you can watch Isomerierungen (retention and inversion).