Chloroperoxidase-mediated asymmetric epoxidation. Synthesis of (R)- dimethyl 2-methylaziridine-1,2-dicarboxylate - A potential α-methylamino acid synthon

Article abstract of DOI:10.1016/S0957-4166(97)00467-9

Methoxycarbonyl-protected methallyl amine serves as an excellent substrate for chloroperoxidase-mediated asymmetric epoxidation. The resulting (R)-epoxide (94% ee) was converted to the title compound in three steps with nearly complete maintenance of stereochemical integrity. Titanium tetrachloride ring-opening of the epoxide provided the chlorohydrin with excellent selectivity and inversion of the stereogenic center. Oxidation with pyridinium dichromate was followed by ring-closure to the aziridine which was esterified in situ with methyl iodide.