Question

3-tert-butylphenol reacts with different halogens by electrophillic substitution under appropriate conditions that are given below:The observed pattern of electrophillic substitution can be explained by

• A. (A) the steric effect of halogen
• B. (B) the steric effect of tert-butyl group
• C. (C) the electronic effect of the phenolic group
• D. (D) the electronic effect of the tert-butyl group

Answer 1

Answer: (A), (C), (D)

(A) the steric effect of halogen

Answer 2

Explanation:
Chloronium ion is least bulky and a tri-substituted product is obtained.(I)Mono substituted product is obtained on iodination because of stearichindrence of the 1+ ion as well as the tertiary butyl group. The hydrogenat the least hindered site, ortho to the -OH group is substituted.(ii)Br+ ion is less bulky and substitution takes place at both ortho and para positions.(iii)Chloronium ion is least bulky and a tri-substituted product is obtained.