Question

Which of the following is the correct order for ease of dehydration

• A. II> III > II > IV
• B. IV > III > II > I
• C. IV > II > III > I
• D. III > IV > II > I

Answer 1

Answer: (B)

The ease of dehydration can be determined by seeing the stability of carbocation as intermediate.

(IV) is most stable due to resonance followed by(III) which is allylic carbocation. Next is(II) as it is a secondary carbocation and least stable is (I) as it is a primary carbocation.
Alternatively, ease of dehydration can be determined from the stability of the product formed.