Question

Consider the above reaction, the major product "P" formed is : 

 

• A. A
• B. B
• C. C
• D. D

Hint:

When faced with a question where the reactant structure or reaction conditions seem incorrect, first re-read carefully. If it remains ambiguous, try to work backward from the options or look for the most stable product. Recognize that exam questions can sometimes contain errors.

Answer 1

The Correct Option is A

The given reaction involves treatment of an $\alpha,\beta$-unsaturated carbonyl compound with concentrated HBr.
In acidic conditions, HBr adds to the double bond via Markovnikov electrophilic addition.
Step 1: Protonation occurs at the carbon atom which leads to the more stable carbocation intermediate.
Step 2: The bromide ion (Br$^-$) attacks the carbocation, forming the more substituted bromo-carbonyl compound.
Addition occurs in such a way that the bromine attaches to the more substituted carbon of the double bond, giving the thermodynamically stable product.
Among the given options, structure (A) corresponds to this Markovnikov addition product and is therefore the major product.