硫酸二甲酯

5,5-dimethyl-oxazolidine-2,4-dione 2-[(1-phenyl-ethylidene)-hydrazone]

5,5-二甲基-2-硫代-1,3-恶唑烷-4-酮

异氰酸甲酯

2-羟基异丁酸乙酯