ENANTIOSELECTIVE EPOXIDATION OF AN ALLYLIC ALCOHOL CATALYZED BY (ACETYLACETONATO)(L-N-METHYLPROLINOL)DIOXOMOLYBDENUM. THE DECREASE OF ENANTIOSELECTIVITY WITH CHEMICAL CONVERSION

Article abstract of DOI:10.1016/S0022-328X(00)98650-9

Epoxidation of 3-methyl-2-buten-1-ol with cumene hydroperoxide catalyzed by MoO2(acac)2 in the presence of L-N-methylprolinol yields epoxy alcohol of 50percent optical purity at relatively low conversions.This enantioselectivity decreases with increase in conversion, which is due to the destruction of the chirality of the catalyst via oxidation of the chiral ligand or its replacement.It is possible to maintain the initial chiral selectivity of 50percent AT over 80percent conversion by periodically adding more chiral ligand.