See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Solution: Identifying the Type of Isomerism **Step 1: Analyze the molecular formula** Both compounds I and II have the same molecular formula: $C_{13}H_{19}BrO_3S$ (same atoms, same count). **Step 2: Identify the key structural difference** - **Compound I**: Br and $CH_3$ groups are on the *same side* of the cyclohexane ring (both equatorial or axial) - **Compound II**: Br is axial and $CH_3$ is equatorial (or vice versa), shown by the wedge/dash notation—they are on *opposite sides* of the ring **Step 3: Classify the isomerism type** Since both compounds: - Have identical molecular formulas - Differ only in the *spatial arrangement* of atoms around the cyclohexane ring (stereochemistry) - Cannot be interconverted by single bond rotation due to ring rigidity This is **stereoisomerism**, specifically **geometrical isomerism** (diastereomerism) based on different spatial orientations around the cyclohexane. **Why not other options?** - (A) Functional groups are identical → not functional isomerism - (B) Both belong to the same chemical class (sulfonate esters) → not metamerism - (C) No chiral centers with different connectivity → not optical isomerism **Answer: (D) Geometrical isomerism** ✓