See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

# Analysis of Hydride Shift Mechanism in Option (C) **Option (C) is incorrect because the hydride shift mechanism is improperly shown.** ## Step-by-step reasoning: **Initial carbocation:** The structure shows a secondary carbocation at the central carbon: $CH_3-\overset{\oplus}{C}(H)-CH_3$ **Hydride shift process:** A hydride ion ($H^-$) from an adjacent carbon migrates to the positively charged carbon to form a more stable carbocation. **Correct mechanism:** The hydride should move from a neighboring carbon TO the carbocation: $$CH_3-\overset{\oplus}{C}(H)-CH_3 \xrightarrow{H^- \text{ shift}} \overset{\oplus}{C}(CH_3)_3 \text{ (tertiary carbocation)}$$ **Why option (C) is wrong:** The diagram shows the hydride shifting FROM the carbocation center carbon TO create $CH_3-CH-CH_2$, which contradicts the hydride shift mechanism. A hydride cannot spontaneously leave a carbocation; it must migrate FROM a neighboring carbon TO stabilize the positive charge. **Why others are correct:** - (A): Friedel-Crafts alkylation ✓ - (B): Aldol condensation mechanism ✓ - (D): Carbanion formation in aldehyde under base ✓ **Answer: C** — The hydride shift is depicted in the wrong direction.