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Haloalkanes and Haloarenes — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistryHaloalkanes and Haloarenes1 Mark
MCQ
By which mechanism does the above reaction proceed?

  • A
    E1​
  • B
    E2​
  • C
    E1​cb
  • D
    $\gamma$-Elimination
✓

Answer

  1. E2​

Explanation:

If the reaction proceeds by E1​ mechanism, then the breaking of C−H and C−D bonds is not involved in the slow step (or rate determining effect). Based on this both products CH2​=CH−CD3​ and CH3​−CH=CD2​ are expected.

However only CH2​=CH−CD3​ is obtained. This indicates that breaking of C−H bond (which is faster than breaking of C−D bond) is involved in the mechanism along-with breaking of C−Br bond.

This indicates E2​ mechanism for elimination.

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