Mechanism of beta-silyl diacyl peroxide decomposition: a mild and stereoselective synthesis of beta-silyl esters.
A novel method for the formation of beta-silyl esters is presented. Mechanistic studies were carried out on the formation and decomposition of beta-silyl diacyl peroxides, showing that the decomposition pathway involves an ionic mechanism that is influenced by the presence of the beta-silyl moiety. These studies exclude a free radical decomposition pathway as evidenced by the absence of chemically induced dynamic nuclear polarization (CIDNP) during the reaction and a strong correlation of the resulting regioisomeric product distribution to sigma(+). This reaction allows for the formation of beta-silyl esters in 45-50% isolated yield with predictable regioselectivity and good to excellent diastereoselectivity. Studies demonstrate that ester products which are formed at benzylic centers have the erythro configuration, whereas ester products formed at alkyl centers have the threo configuration.
Masterson
Douglas S
DS
Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA.
Porter
Ned A
NA
D004952:Esters / Q000138:chemical synthesis*; D015394:Molecular Structure; D010545:Peroxides / Q000737:chemistry*; D013237:Stereoisomerism
D004952:Esters; D010545:Peroxides