Question

Which of the following alkyl halides is most likely to undergo an E1 elimination reaction?A) 1-chloro-2-methylpropane B) 2-bromo-2-methylbutane C) 1-iodo-3-methylpentane D) 1-bromo-3-methylbutane Explain your answer.

Answer 1

B  2-bromo-2-methylbutaneAn E1 elimination reaction involves the formation of a carbocation intermediate, which then undergoes deprotonation to form the alkene product. The stability of the carbocation intermediate is crucial for the reaction to proceed. Carbocations are more stable when they are more substituted, as the electron-donating alkyl groups help to stabilize the positive charge.Let's analyze each option:A  1-chloro-2-methylpropane: The carbocation formed would be a secondary carbocation.B  2-bromo-2-methylbutane: The carbocation formed would be a tertiary carbocation.C  1-iodo-3-methylpentane: The carbocation formed would be a secondary carbocation.D  1-bromo-3-methylbutane: The carbocation formed would be a primary carbocation.Out of these options, 2-bromo-2-methylbutane  option B  would form the most stable tertiary carbocation, making it the most likely to undergo an E1 elimination reaction.