An unsaturated hydrocarbon A (C6H10) readily gives B on treatment with NaNH2 in liquid NH3. When B is allowed to react with 1− chloropropane a compound C is obtained. On partial hydrogenation in the presence of Lindlar catalyst, compound C gives D (C9H18). On ozonolysis, D gives 2, 2-dimethyl propanal and l−butanal. With proper reasoning give the structures of A,B,C and D.