MHT CET202522 Apr 2025Evening ShiftChemistryGeneral Organic ChemistryActual
Which of the following alkenes does NOT exhibit cis-trans isomerism ?
Options
- ABut-1-ene
- BBut-2-ene
- C3,4-Dimethylhex-3-ene
- DPent-2-ene
Correct answer
A. But-1-ene
Step-by-step solution
Cis-trans isomerism requires that each carbon of the double bond be bonded to two distinct groups. But-1-ene, with structure CH ₂= CH - CH ₂- CH ₃ , has both hydrogens attached to the first carbon and thus fails this condition. But-2-ene, 3,4-dimethylhex-3-ene, and pent-2-ene all meet the requirement with different substituents on each olefinic carbon, so only but-1-ene lacks geometric isomers.