Abstract
Co(II)-catalyzed peroxidation of dienes including (S)-limonene in the presence of molecular oxygen and triethylsilane provided in each case the corresponding 2,3-dioxabicyclo[3.3.1]nonane derivatives via theintramolecular cyclization of the unsaturated peroxy radical intermediates.The product composition was remarkably influenced by the structure of thedienes, the nature of the solvents (1,2-dichloroethane or ethanol), and the concentration of the substrates and the catalyst (Co(modp)2 or Co(acac2).In connection with the notable solvent effect, we undertook the peroxidationof a mixture of 1-decene and 1-decanol in the presence of Co(modp)2) for 15 h and found that decyl triethylsilyl ether (23%) was obtained together with 2-dodecyl triethylsilyl peroxide (90%), suggesting in an alcoholic solvent(i) ligand exchange between Co(III)-alkylperoxy complex (derived from analkene) and the alcohol and (ii) metal exchange between Co(III)-alkoxy complex and triethylsilane is important.
