Criegee rearrangements

Peroxyeslers may undergo non-radical decomposition via ibe Criegee rearrangement (Scheme 3.35). This process is analogous to the earboxy inversion process described for diacyl peroxides (see 3.3.2.1,3) and probably involves ionic intermediates. 

The method is particularly useful for preparation of 6-nitrogalactopyranosides, which cannot be prepared by the usual Komblum route (Sn2 displacement of I by AgN02). Criegee rearrangement of a-alkoxy hydroperoxidesf The a-alkoxy hydroperoxides formed by ozonolysis in CH,OH rearrange on treatment with Ac,0 to esters or lactones. 

Criegee rearrangement of a-alkoxy hydroperoxides.4 The a-alkoxy hydroperoxides formed by ozonolysis in CH3OH rearrange on treatment with Ac20 to esters or lactones. 

An alternative mechanism involves nucleophilic attack of the C-3 of indole on the distal oxygen atom of the bound O2 coupled with deprotonation. Two pathways to the Al-formylkynureiune product have been proposed, one involves a Criegee rearrangement-type mechaiusm and the other involves an endoperoxide intermediate Further studies are required to estabhsh the exact mechaiusm of product formation. 

Sigmatropic rearrangement 1.12.42 Epoxy silyl ether rearrangement 1.1.2.43 Criegee rearrangement... 

The acylations of a-alkoxy hydroperoxides such as (79) furnish peroxy esters that are related to the intermediate produced in the Baeyer-Villiger reaction. " The peroxy ester undergoes the Criegee rearrangement to a dioxonium ion which in turn is converted into an ester. Thus, ozonolysis of (+)-( )-dihydrocarvone (78) affords a 1 1 mixture of diastereomers (79). Acetylation and rearrangement... 

Goodman, R. M., Kishi, Y. Experimental Support for the Primary Stereoelectronic Effect Governing Baeyer-Villiger Oxidation and Criegee Rearrangement. J. Am. Chem. Soc. 1998, 120, 9392-9393. 

Criegee rearrangement to give an anhydride intermediate, followed by the partial exchange of the iron(III) 0-hydroxide with solvent water. ... 

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