NTA Abhyas JEE Main2020ChemistryHaloalkanes and HaloarenesPractice
Which of the following is correct?
Options
- AVinyl chloride is more reactive than ethyl chloride in S N 2
- BVinyl chloride is more reactive than ethyl chloride in S N 1
- Callyl chloride is less reactive than n-propyl chloride in S N 1
- Dallyl chloride is more reactive than n-propyl chloride in S N 2
Correct answer
D. allyl chloride is more reactive than n-propyl chloride in S N 2
Step-by-step solution
As the electronegativity order of hybridized carbons is s p > s p 2 > s p 3 so in an allylic halide, such as C H 2 = C H - C H 2 - C l , the alpha carbon is much more partially positive than the alpha carbon in(n-propyl chloride) CH 3 − CH 2 −  CH 2 − Cl . Therefore, the attacking nucleophile will be attracted to the alpha carbon more in the allylic halide compound than in the primary halide. It means allylic halides tend to follow S N 2 pathways more than primary halides.