1.Reaction of chlorine with compounds containing the CCl2=CH group in a medium of anhydrous formic acid followed by treatment with water gives α -chloro carboyxlic acids in good yields.2.In this way, from 1,1,3-trichloropropene, l,l-dichloro-3-methoxypropene, 3,3-dichloroallyl formate, 1,1,5-trichloro-1-pentene, 5,5-dichloro-4-pentenyl formate, 1,1,7-trichloro-1-heptene, and 1,1,9-trichloro-1-nonene the following α-chloro carboxylic acids were prepared: 2,3-dichloro- and 2-chloro-3-methoxy-propionic acids, 2-chlorohydracrylic acid formic ester, 2,5-dichlorovaleric acid, 2-chloro-5-hydroxyvaleric acid formic ester, 2,7-dichloroheptanoic acid, and 2,9-dichlorononanoic aci