IUPAC name of the compound CH3−C|Cl−CH=CH−COOH is

[Step 1]:The given compound is carboxylic acid.Aliphatic carboxylic acids are named by replacing the ending –e in the name of the  corresponding alkane with –oic acid.In numbering the carbon chain, the carboxylic carbon is numbered one.The substituent –Cl is located at C4.Double bond (en) is at C2.