`X underset("ether")overset(Mg)rarrY underset(H^(+))overset("Dry " CO_(2))rarr X overset("hot " KMnO_(4))rarrP`
The two isomeric compounds which will give the same tricarboxylic acid after the above sequence of reactions, are :

underset(OH^(-))overset(KMnO_(4))rarr A underset(H_(2)SO_(4))overset(Dil)rarr B

underset("dry ether")overset(Mg)rarr (A) overset(CH_(3)I)rarr (B) , Product (B) is :

CH_3 Br underset("Dry ether")overset(Mg)to CH_2MgBr overset(D_2O)to B

In the reaction : CH_(3)CH_(2)Br underset("Ether")overset(Mg)rarr X underset("Ether")overset(CH_(3)Br)rarr Y + MgBr_(2) Y is :

CH_(3)-CH=CH_(2) underset("h v (low conc.)")overset(Br_(2))rarr underset("Dry ether")overset(Mg)rarr underset(NH_(4)Cl)overset(CH_(3)-overset(O)overset(||)(C)-CH_(3))rarr underset(Delta)overset(H^(+))rarr underset("(major)")((X)) End product (X) of the above reaction is :

overset (Mg//ether)rarr overset (D_(2)O)rarr overset (Na//ether)rarr (X) The compound (X) is:

CH_(3)-CH=CH_(3)underset(underset(("low conc."))(hv))overset(Br_(2))rarr underset("Dry ether")overset(Mg)rarr underset(NH_(4)Cl)overset(CH_(3)-overset(O)overset(||)(C)-CH_(3))rarrunderset(Delta)overset(H^(+))rarrunderset(("major"))((X)) End product (X) of the above reaction is :

2Ph-overset(O)overset(||)(C)-CH_(3)overset(Mg-Hg)underset(H_(2)O)rarroverset(Conc.H_(2)SO_(4))underset(Delta)rarr overset(KMnO_(4)H^(o+))rarr The final product is