Let's synthesize each compound in **2 steps** from a suitable alkyl halide (or tosylate), explaining each step. --- ## 1. Cyclohexyl ethyl ether ### Step 1: Prepare cyclohexanol - **Start with:** cyclohexyl bromide (alkyl halide) - **Reagent:** NaOH (aq) - **Reaction:** Nucleophilic substitution ``` cyclohexyl bromide + NaOH → cyclohexanol ``` **Explanation:** The hydroxide ion replaces the bromide via SN2, forming cyclohexanol. ### Step 2: Williamson Ether Synthesis - **Reagent:** 1-bromoethane (ethyl bromide), NaH - **Reaction:** Ether formation (Williamson synthesis) ``` cyclohexanol + NaH → cyclohexyloxide anion cyclohexyloxide anion + 1-bromoethane → cyclohexyl ethyl ether ``` **Explanation:** The alkoxide ion reacts with ethyl bromide to give the ether. --- ## 2. 2-Butanol ### Step 1: Prepare 2-bromobutane - **Start with:** 2-butene (alkene) - **Reagent:** HBr - **Reaction:** Markovnikov addition ``` 2-butene + HBr → 2-bromobutane ``` **Explanation:** Bromine adds to the more substituted carbon. ### Step 2: Nucleophilic Substitution (SN2) - **Reagent:** NaOH (aq) - **Reaction:** Substitution ``` 2-bromobutane + NaOH → 2-butanol ``` **Explanation:** Hydroxide replaces bromine to give 2-butanol. --- ## 3. Equimolar mixture of cis/trans 1-methoxy-2-methylcyclohexane ### Step 1: Prepare 1-bromo-2-methylcyclohexane - **Start with:** 2-methylcyclohexanol - **Reagent:** PBr₃ - **Reaction:** Alcohol to alkyl bromide ``` 2-methylcyclohexanol + PBr₃ → 1-bromo-2-methylcyclohexane ``` **Explanation:** Bromine replaces the alcohol group. ### Step 2: Nucleophilic Substitution with Methoxide - **Reagent:** NaOCH₃ (sodium methoxide) - **Reaction:** SN1 (racemization at C1) ``` 1-bromo-2-methylcyclohexane + NaOCH₃ → 1-methoxy-2-methylcyclohexane (cis + trans, 50:50) ``` **Explanation:** The SN1 mechanism gives a racemic (cis/trans) mixture. --- ## 4. 2-Methylpent-2-ene ### Step 1: Prepare 2-bromo-2-methylpentane - **Start with:** 2-methylpentane - **Reagent:** Br₂, hv (light) - **Reaction:** Radical bromination ``` 2-methylpentane + Br₂ (hv) → 2-bromo-2-methylpentane ``` **Explanation:** Bromine adds at the most substituted carbon. ### Step 2: Elimination (E2) - **Reagent:** NaOEt (sodium ethoxide) in ethanol - **Reaction:** Dehydrohalogenation ``` 2-bromo-2-methylpentane + NaOEt → 2-methylpent-2-ene ``` **Explanation:** Strong base removes a proton, eliminating bromide and forming the alkene. --- ## 5. 1-Phenyl-1-propene ### Step 1: Prepare 1-phenyl-1-propyl bromide - **Start with:** 1-phenyl-1-propanol - **Reagent:** PBr₃ - **Reaction:** Alcohol to bromide ``` 1-phenyl-1-propanol + PBr₃ → 1-phenyl-1-propyl bromide ``` **Explanation:** Alcohol is converted to bromide. ### Step 2: Elimination (E2) - **Reagent:** KOtBu (potassium tert-butoxide) - **Reaction:** Dehydrohalogenation ``` 1-phenyl-1-propyl bromide + KOtBu → 1-phenyl-1-propene ``` **Explanation:** Strong base eliminates HBr to form the alkene. --- ## **Final Answers** Each target compound can be synthesized in **2 steps** from a suitable alkyl halide (or tosylate), as detailed above, using standard organic transformations (substitution, elimination, ether formation).