Saegusa-Ito Oxidation

• General Characteristics

In the Saegusa-Ito reaction, silyl enol ethers are converted into corresponding α,β-unsaturated ketones using Pd(OAc)₂.

There are modified versions developed to avoid the use of the expensive palladium reagent in stoichiometric amount. For example, there are a method that uses O₂ as a reoxidant in DMSO (the Larock modification), a method that uses inexpensive Cu(II) as a reoxidant, and a method that uses allyl vinyl carbonates instead of silyl enol ethers (the Tsuji modification).

• General References

・Ito, Y.; Hirao, T.; Saegusa, T. J. Org. Chem. 1978, 43, 1011. DOI:10.1021/jo00399a052
・Larock Modification: Larock, R. C.; Hightower, T. R.; Kraus, G. A.; Hahn, P.; Zheng, D. A. Tetrahedron Lett. 1995, 36, 2423. DOI:10.1016/0040-4039(95)00306-W
・Tsuji Modification: Shimizu, I.; Minami, I..; Tsuji, J. Tetrahedron Lett. 1983, 24, 1797. DOI:10.1016/S0040-4039(00)81773-6

• Reaction Mechanism

• Examples

An application in the total synthesis of norzoanthamine.^[1]

• Experimental Procedure

• Experimental Tips

• References

[1] Miyashita, M.; Sasaki, M.; Hattori, I.; Sakai, M.; Tanino, K.Science 2004, 305, 495. DOI: 10.1126/science.1098851

• Related Books

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oxidation of silyl enol ethers, synthesis of alpha-beta unsaturated ketones