question_answer

The order of reactivity of the following alcohols towards cone. \[HCl\] is

(I)	(II)
(III)	(IV)

A) I>II>III>IV                  

B) I>III>II>IV

C) IV>III>II>I                  

D) IV>III>I>II  

Correct Answer: C

Solution :

[c] The order of reactivity depends upon the stability of the carbocations formed. Remember that presence of electron-withdrawing  roup intensifies i.e., destabilises the carbocation thus (i) and (ii) are less stable than (iii). Further (i) is less stable than (ii) because -I effect is more pronounced in (i) due to less distance between F and positive charge. Thus the stability order of the four carbocations and reactivity of their parent alcohols will be IV > III > II > I