Criegee rearrangement

What is Criegee rearrangement?

In 1944, Criegee was the first to report on the Criegee rearrangement, which involves the transformation of peroxy ester into ketone, ester, or carbonate, and alcohol through oxygen insertion or consecutive oxygen insertion.

This reaction is named after Criegee and primarily occurs through the reaction between peracid and tertiary alcohol, leading to the formation of peroxy ester.

Criegee rearrangement
Criegee rearrangement

The Baeyer-Villiger oxidation is a subset of the Criegee rearrangement, and peracids such as p-nitroperbenzoic acid and trifluoroperacetic acid are commonly used. During the rearrangement, the migrating group moves from a position anti-periplanar to the dissociating oxygen-oxygen bond of the peroxy ester, facilitated by the electron-donating ability of the migrating group. This reaction occurs through an ionic mechanism, with the second step of migration believed to be concerted. Allylic hydroperoxides yield cyclic or acyclic enol ethers, and the isopropenyl group can be readily removed.

Notably, the Criegee rearrangement differs from the Baeyer-Villiger oxidation in that consecutive oxygen insertion occurs in the former, whereas no oxygen insertion has been reported for ketones and aldehydes. Additionally, the starting material for the Criegee rearrangement is tertiary alcohols, while ketones are used in the Baeyer-Villiger oxidation.

References

Criegee, R. (1945), Ein neuer Weg in die Cyclodecanreihe. [A new way into the cyclodecane series.] Ber. dtsch. Chem. Ges. A/B, 77: 722-726. https://doi.org/10.1002/cber.19450770912

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