Chan rearrangement

What is Chan rearrangement?

In 1984, Chan first reported the Chan rearrangement, which is a rearrangement of α-acyloxy-acetates to α-hydroxy-β-keto-esters induced by a base. It should be noted that amino ketone can also be prepared under similar conditions. The intermediate enediolate, formed in the presence of an excess amount of base (usually LDA), can react with Me3SiCl or Ac2O to produce the corresponding trimethylsilyl or acetyl derivatives.

Chan rearrangement
Chan rearrangement

Chan rearrangement is a convenient method for constructing an array of three contiguous oxygenated carbons and has been successfully used in the synthesis of various natural products, including the indole-bisoxazole fragment of diazonamide A, (+)-aplasmomycin, boromycin, taxol, and polyoxazole.

References

Lee, S. D.; Chan, T. H. and Kwon, K. S., Rearrangement of α-acyloxyacetates into 2-hydroxy-3-ketoesters Tetrahedron Lett., 1984, 25, 3399-3402
DOI: 10.1016/S0040-4039(01)91030-5

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