Question

Hyperconjugation involves delocalisation of:

(i) Electrons of carbon-hydrogen σ bond of an alkyl group directly attached to an atom of unsaturated system.

(ii) Electrons of carbon-hydrogen σ bond of alkyl group directly attached to the positively charged carbon atom.

(iii) π-electrons of carbon-carbon bond.

(iv) Lone pair of electrons.

Answer 1

(i) Electrons of carbon-hydrogen σ bond of an alkyl group directly attached to an atom of unsaturated system.

(ii) Electrons of carbon-hydrogen σ bond of alkyl group directly attached to the positively charged carbon atom.

Explanation:

since hyperconjugation involves the delocalization of electrons of C—H bond of an alkyl group directly attached to an atom of unsaturated system or to an atom with an unshared p-orbital. The electrons of C—H bond of the alkyl group enter into partial conjugation with the attached unsaturated system or with the unshared p-orbital. This is a permanent effect. Hyperconjugation can be shown as-