Practice Problems

Chapter 6 Practice Problems

Chapter 6 Practice Problems (SN1/SN2/E1/E2)

  1. SN1 vs SN2: Predict mechanism and major product for:
    a) 1-bromopropane + NaOH (DMSO, 25 °C).
    b) t-butyl bromide + H₂O (30 °C).
    c) Bromobenzene + NaN₃.
    d) 2-bromobutane + NaI (acetone).

  2. E2 vs E1 conditions: Which favors E2?
    a) 2-bromopentane + KOtBu/t-BuOH (heat).
    b) t-butyl bromide in ethanol, no strong base, RT.
    c) Primary bromide with NaNH₂.

  3. E2 stereochemistry: 1-bromo-1,2-diphenylethane + strong base → major alkene? Explain cis/trans preference.

  4. SN1 rearrangement: 3-bromo-2,2-dimethylpentane in 80% EtOH/20% H₂O. Show possible rearranged carbocation and give substitution/elimination products.

  5. Competing pathways: Dominant mechanism/products for:
    a) 1-chlorobutane + NaOEt (EtOH).
    b) 2-chloro-2-methylpropane + NaOH (H₂O).
    c) 2-bromobutane + heat in MeOH.
    d) Neopentyl bromide + NaSH (DMSO).

  6. Solvent effect: 1-bromooctane + NaN₃ – faster in water or DMF? Why?

  7. Reaction map exercise: From 2-bromopentane, choose reagents to get:
    a) 2-pentanol, b) 1-pentene, c) trans-2-pentene (major), d) pentane. Give mechanisms.

  8. SN1/E1 mix: 2-bromo-3,3-dimethylbutane in aqueous ethanol → name the alcohol and alkene formed; explain via carbocation intermediate.