Elimination reactions Knowledge-Based Practice

Questions

1. 1.

   Which alkene is the major product obtained from the acid-catalyzed dehydration of 3,3-dimethylbutan-2-ol?

   • A) 3,3-dimethylbut-1-ene
   • B) 2,3-dimethylbut-2-ene
   • C) 2,3-dimethylbut-1-ene
   • D) 2-methylpent-2-ene
2. 2.

   Which of the following bases predominantly promotes the formation of the less substituted alkene (Hofmann product) in the E2 elimination of 2-bromo-2-methylbutane?

   • A) Sodium hydroxide ($\text{NaOH}$)
   • B) Sodium methoxide ($\text{NaOMe}$)
   • C) Sodium ethoxide ($\text{NaOEt}$)
   • D) Potassium tert-butoxide ($t\text{-BuOK}$)
3. 3.

   In a concerted bimolecular elimination (E2) reaction, which spatial orientation between the $\beta$-hydrogen atom and the leaving group is required to achieve optimal orbital overlap in the transition state?

   • A) Syn-clinal conformation
   • B) Perpendicular (orthogonal) conformation
   • C) Anti-periplanar conformation
   • D) Gauche conformation
4. 4.

   Which of the following alkyl halides undergoes elimination most rapidly via an E1 mechanism in a polar protic solvent?

   • A) 1-Chlorobutane
   • B) 2-Chlorobutane
   • C) 2-Chloro-2-methylpropane
   • D) 1-Chloro-2-methylpropane
5. 5.

   Which of the following alkenes is the major product formed when 2-bromobutane is heated with alcoholic potassium hydroxide ($\text{KOH}$)?

   • A) But-2-ene
   • B) But-1-ene
   • C) Butan-2-ol
   • D) Butane

Answers and step-by-step solutions appear after you finish the test.