Question

Which one of the following does not exhibit hyperconjugation?

• A. Ethanal
• B. Allylene
• C. Isobutylene
• D. Trifluro acetaldehyde

Answer 1

The correct option is D Trifluro acetaldehyde

A) Ethanal $\left({CH}_{3}CHO\right)$ exhibits hyper conjugation having three hyper conjugative $H$ atoms.

B) Allylene exhibits hyper conjugation having $3$ hyper conjugative $H$ atoms.

C) Isobutylene exhibits hyper conjugation six hyper conjugative $H$ atoms.

D) Trifheroacetaldehyde does not exhibit hyper conjugation because positive charge can not be developed on $F$ atom due high electronegativity of $F$.

$F^{+}$ is highly unstable.

Correct answer will be D.