Paragraph: Treatment of benzene with CO / HCl in the presence of anhydrous AlCl 3 / CuCl followed by reaction with Ac 2 O / NaOAc gives compound X as the major product. Compound X upon reaction with Br 2 / Na 2 CO 3 , followed by heating at 473   K with moist KOH furnishes Y as the major product. Reaction of X with H 2 / Pd - C , followed by H 3 PO 4 treatment gives Z as the major product Question : The compound