Natural rubber on complete ozonolysis \( \left(\mathrm{O_3/Zn - H_2O}\right) \) gives compound \( X \) as the major product. \( X \) gives positive iodoform and Tollen’s tests. \( X \) on heating with aqueous \( \mathrm{NaOH} \) gives \( Y \) as the major product. \( Y \) is:
