Syn-Dihydroxylation of Alkenes Using a Sterically Demanding Cyclic Diacyl Peroxide

The syn-dihydroxylation of alkenes is a highly
valuable reaction in organic synthesis. Cyclic acyl peroxides (CAPs)
have emerged recently as promising candidates to replace the commonly
employed toxic metals for this purpose. Here, we demonstrate that
the structurally demanding cyclic peroxide spiro­[bicyclo[2.2.1]­heptane-2,4′-[1,2]­dioxolane]-3′,5′-dione
(P4) can be effectively used for the syn-dihydroxylation of alkenes. Reagent P4 also shows an
improved selectivity for dihydroxylation of alkenes bearing β-hydrogens
as compared to other CAPs, where both diol and allyl alcohol products
compete with each other. Furthermore, the use of enantiopure P4 (labeled P4′) demonstrates the potential
of P4′ for a metal-free asymmetric syn-dihydroxylation of alkenes.