2-methyl-4,5-dioxo-cyclopentane-1,3-dicarboxylic acid dimethyl ester 、
sodium methylate 、
碘甲烷 生成 1,2-dimethyl-4,5-dioxo-cyclopentane-1,3-dicarboxylic acid dimethyl ester 、 4-methoxy-1,2-dimethyl-5-oxo-cyclopent-3-ene-1,3-dicarboxylic acid dimethyl ester