Reaction Using ^-Ketoesters

The reaction using ^-ketoesters resulted in 1,2-dioxan-3-ols in a comparable or better yield than that using the 1,3-diketones (Scheme 8) [80-82]. The cyclic peroxidation occurred at the more electrophilic ketocarbonyl carbon than the ester carbonyl carbon.

Cyclic ^-ketoesters and aryl-substituted cycloalkenes also afforded the corresponding bicyclic endoperoxides and spirodioxanes (Scheme 9).

When the reaction was carried out using more than one equivalent of man-ganese(III) acetate, the yield of the cyclic peroxides was sometimes medium or poor, and a considerable amount of by-products was formed. The major by-products were dihydrofurans, benzophenones, and glycol monoacetates.

R1 R2


AcOH air, rt

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