Prilezhaev Reaction

The epoxidation of an alkene with peracid to give an oxirane. The commercially available mCPBA is a widely used reagent for this conversion, while magnesium mono-perphthalate and peracetic acid are also employed.

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Mechanism of the Prilezhaev Reaction

Peracids tend to adopt an intramolecularly hydrogen-bonded conformation in solution, and the high degree of polarisation results in an electrophilic oxygen atom that is able to add to alkenes.

Hydrogen peroxide in combination with various additional catalysts may also be used in epoxidations.

The transition state, in which oxygen is added and the proton is shifted simultaneously, resembles a butterfly and is known as the "Butterfly Mechanism":

Recent Literature

Epoxidation of Olefins with a Silica-Supported Peracid
R. Mello, A. Alcalde-Aragonés, M. E. González Núñez, G. Asensio, J. Org. Chem., 2012, 77, 6409-6413.

Phase-Vanishing Methodology for Efficient Bromination, Alkylation, Epoxidation, and Oxidation Reactions of Organic Substrates
N. K. Jana, J. G. Verkade, Org. Lett., 2003, 5, 3787-3790.

Diastereoselective Epoxidation of Allylic Diols Derived from Baylis-Hillman Adducts
R. S. Porto, M. L. A. A. Vasconcellos, E. Ventura, F. Coelho, Synthesis, 2005, 2297-2306.