question_answer

Match the items given in column I with those in column II and choose the correct option given below.

Column I (Reactions)	Column II (Characteristics)
I.	(P) Hofmann elimination, one product
II.	(Q) \[{{S}_{N}}1\] and \[{{E}_{1}}\] and 6 products
III.	(R) \[{{E}_{1}}CB,\] carbanion
IV.	(S) Non-classical carbonium ion, racemate

Options:

A)  I - Q               II - P       III - R      IV - S

B)  I - P                II - S       III - Q      IV - R

C)  I - R                II - Q       III - P      IV - Q

D)  I - S                II - R       III - S      IV - P

Correct Answer: A

Solution :

[a] \[I-Q\]

II - P

Major product of E2 dehydro-halogenation of RF is the least substituted alkene (i,e., Hofmann elimination), irrespective of base is either bulky (e.g., \[t-Bu{{O}^{\bigcirc -}}\]). Or non bulky (e.g., \[Et{{O}^{\bigcirc -}}\])

III - R

Strong EWG (e.g., \[-N{{O}_{2}}\] or \[-\overset{O}{\mathop{\overset{||}{\mathop{S}}\,}}\,-\] group) and poor leaving group (e.g., \[\overset{\bigcirc -}{\mathop{F}}\,\] or \[Ph{{O}^{\bigcirc -}}\]group) favours \[E1CB\]reaction.

IV-S