The correct option is
B Given: Carbonyl compound P gives iodoform test.
For a compound to give iodoform test, it should have a methyl ketone group (
CH3CO).
Among (i-iii). Only (ii) and (iii) have a methyl keto group hence, (ii) or (iii) can be the compound (P).
Further, we will proceed with possibilities of both (ii) and (iii).
'P' on reaction
CH3MgBr gives a nucleophilic addition product.
Next step is dehydration with
H2SO4 which is a E1 elimination reaction. From the option, we can say that dehydration occurs by a new ring formation.
Formed product 'Q' undergo ozonolysis to give dicarbonyl compound 'R'.
It is given that compound 'R' undergoes intramolecular aldol reaction. For a molecule to undergo aldol reaction, it should have an alpha hydrogen with respect to carbonyl group.
Compound 'R' from (iii) does not have an alpha hydrogen with respect to carbonyl group, hence, compound 'P' should be (ii).
'R' from (ii) undergoes intramolecular aldol reaction form 'S'
Hence, correct answer is (b)