甲醇

3-tert-butyl-3-methyl-3H-pyrazole-4,5-dicarboxylic acid dimethyl ester

2-methoxy-2,5-dimethyl-5-(1,1-dimethylethyl)-Δ3-1,3,4-oxadiazoline

丁炔二酸二甲酯

2-methoxy-2,5-dimethyl-5-(1,1-diphenylmethyl)-Δ3-1,3,4-oxadiazoline