Archiral acetic acid) alkyl, alkylphenyl and phenyl esters, and a simple and efficient method for the synthesis of both enantiomers of homocitric acid gamma-lactone and the corresponding salts from these esters are described. A surface of the preliminary metal layer having uneven portions is etched to remove the uneven portions and to form a metal layer having an improved surface morphology. Adhesive is applied on inner surfaces of the outer panels.