Sure! Let’s work through the first part of the problem (2a) in **2 steps**, with explanations after each step, and the final answer at the end: --- ## 2a) Reaction: Cyclohexyl bromide + KOtBu/tert-Butanol ### **Step 1: Identify the Reaction Type** - **KOtBu (potassium tert-butoxide)** is a strong, bulky base. - **tert-Butanol (t-BuOH)** is a polar protic solvent. - With a secondary alkyl halide (bromocyclohexane), a strong bulky base like KOtBu favors **E2 (elimination, bimolecular)** over substitution, because the base is too bulky for SN2, and the strong base disfavors SN1/E1. #### **Explanation:** The bulky base will abstract a proton from the β-carbon, leading to the formation of an alkene via the E2 mechanism. The most accessible β-proton will be removed, leading to the less substituted (Hofmann) alkene as the **major** product, and the more substituted (Zaitsev) alkene as the **minor** product, since steric hindrance blocks the more substituted β-hydrogen. --- ### **Step 2: Draw the Products** - **Product A (major):** Less substituted (Hofmann) alkene - **Product B (minor):** More substituted (Zaitsev) alkene Draw the following: - **Product A (major):** 1-cyclohexene (double bond between C1 and C2) - **Product B (minor):** 3-cyclohexene (double bond between C2 and C3) #### **Explanation:** - The major product (Hofmann) results from elimination at the less hindered β-carbon, so the double bond forms at the terminal carbon (1-cyclohexene). - The minor product (Zaitsev) forms when the base removes a more hindered β-hydrogen, giving the more substituted double bond (3-cyclohexene). --- ## **Final Answer:** **Product A (major):** - 1-cyclohexene (double bond between C1 and C2) **Product B (minor):** - 3-cyclohexene (double bond between C2 and C3) **Explanations:** - **Step 1:** KOtBu is a strong, bulky base, so E2 elimination is favored, especially at the less hindered position (Hofmann product). - **Step 2:** The double bond forms at the less substituted position for the major product, and at the more substituted position for the minor product. --- Let me know if you'd like to see the arrow-pushing mechanism (part c), or want to proceed to part b!