To investigated the hydrolysis mechanism of a new disinfection by-product,TCMCD,hydrolysis was conducted at different pH and temperature.TCMCD undergoes spontaneous and irreversible hydrolysis with the pseudo-first-order reaction.The hydrolysis products are 2,5-dichloro-3-hydroxy-4-methoxy-cyclopenta-2,4-dienone(DHMCD,compound 1)and 3-chloro-2-hydroxy-4-methoxy-5-oxo-2,5-dihydro-furan-2-carboxylic acid(CHMDFC,compound 2)or their enantiomers.The formation of CHMDFC is the first step of a secies reaction,CHMD...