Question

Which of the following would give Hofmann alkene?

• A.
• B.
• C.
• D.

Answer 1

Answer: (A), (C)

a. The oxidation of $3^{\circ }$ amine to amine oxide followed by Cope reaction on heating gives Hofmann alkene (less substituted)

b. (II) will not give Hoffmann alkene. Benzylic $H$ atom is more acidic due to (-I) effect of Ph. (II) would give

c. (III) will give Hofmann alkene $C{H}_2=C{H}_2$
d. (IV) will not give Hofmann alkene (Cope reaction). Same explanation as in (b) above