How many compounds among the following compounds show inductive, mesomeric as well as hyperconjugation effects? ,ABCDE
Answer: 4
Solution
A compound shows inductive, mesomeric AND hyperconjugation only if it has all three: a polar σ-framework, a conjugated π/lone-pair for resonance, and α C–H to an sp² centre. Counting the given structures that satisfy all three gives 4.