A convenient synthesis of the title nitrone is reported. The sequence starts from ethyl l- pyroglutamate as the source of chirality and the key step is the generation of an unstable α- methoxy-N-carboxylate ion, which readily decomposes to an imine. The oxidation of the imine with methyl (trifluoromethyl) dioxirane provides the enantiopure nitrone, which is trapped with dimethyl acetylenedicarboxylate.
