Question

Observe the following reaction sequence (major product). \[ \mathrm{CH_3CH_2CH_2Br} \xrightarrow{\mathrm{HBr}} Y \xrightarrow[\text{major}]{\mathrm{alc.\ KOH}} Z \] Correct statement regarding \(Z\) is

• A. Number of \(\sigma\) bonds in it is two
• B. Number of hyperconjugative resonance structures possible for it is 6
• C. It does not exhibit cis-trans isomerism
• D. It is the chain isomer of \(X\) \bigskip

Hint:

For alkenes, the number of hyperconjugative structures is approximately equal to the number of \(\alpha\)-hydrogen atoms attached to the carbon adjacent to the double bond.

Answer 1

The Correct Option is B

Step 1: Propene + HBr → 2-bromopropane (Y). Alc. KOH → propene (Z). Propene has 6 α-H, so 6 hyperconjugative structures. Cannot show cis-trans, not chain isomer of but-2-ene.

Step 2: Write the final answer. \(\boxed{\text{Number of hyperconjugative resonance structures possible is }6.}\)