H Cyclic Esters COOH Reaction of-OH and -COOH on same molecule produces a cyclic ester,lactone. To name,add word lactone to the IUPAC acid name or replace the -ic acid of common name with -olactone. H3C 4-hydroxy-2-methylpentanoic acid lactone a-methyl-y-valerolactone CH3 => Chapter 21 4Chapter 21 4 Cyclic Esters • Reaction of -OH and -COOH on same molecule produces a cyclic ester, lactone. • To name, add word lactone to the IUPAC acid name or replace the -ic acid of common name with -olactone. O O H3 C CH3 4-hydroxy-2-methylpentanoic acid lactone -methyl--valerolactone =>