i. In propene, CH3 – CH = CH2 , one of the sp2 hybridized carbon atom of the double bond is attached to sp2 hybridized carbon atom of methyl group.
ii. One of the C-H bonds of the methyl group can align in plane of the p orbital of sp2 hybridized C-atom and the electrons constituting the C-H bond in plane with this p orbital can then be delocalized into the p orbital.
iii. Therefore, hyperconjugation arises due to the partial overlap of a C-H bond with the p orbital of an adjacent sp2 hybridized carbon atom.
iv. Hyperconjugation (no bond resonance) structures for propene can be represented as:
