Cyclic peroxyhemiketals

Quite recently, List and coworkers observed that when hydrogen peroxide is used as an oxidant, the same reaction furnishes stable and isolable cyclic peroxyhemike-tals [26]. When using the primary amine catalyst 20-trichloroacetic acid (10 mol%), the oxidation of both linear and branched acyclic enones with aqueous hydrogen peroxide (3 equiv) at 30 °C in dioxane gave the peroxyhemiketals 26 in reasonable yields with high enantioselectivities (94—95% ee) (Scheme 5.20). Cyclic peroxyhemiketals were further transformed via a simple protocol (treatment with 1 N NaOH)... 

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