Let us consider the formula of C5H9‌Cl which is optically active. Optically active means molecule does not contain plane of symmetry. So, possible optically inactive structure of C5H9‌Cl is
When, ' X′ react with 1 mole of H2, it converted into optically inactive compound ' Z '
Same as (X),(Y) is optically active and give compound (P) which is inactive.
When ' Y′ react with 1 mole of H2, it will give ' P which is optically active. So, ' P ' is
