See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# IUPAC Nomenclature of the Given Compound **Step 1: Identify the parent chain** Count the longest carbon chain containing both the double bond and hydroxyl group: 5 carbons → **pent** **Step 2: Identify functional groups and their priorities** - Double bond ($C=C$): **-en-** - Hydroxyl group ($-OH$): **-ol** (higher priority than alkene) **Step 3: Number the chain for lowest locants** Number from the end closest to the $-OH$ group: - Position 2: $-OH$ group - Position 3: $C=C$ double bond - Numbering gives: **pent-3-en-2-ol** **Step 4: Assign stereochemistry** For the $-OH$ at C2: - $HO$ and $H$ are both low priority → ignore them - Compare the two groups on C2; using CIP rules: the group toward C3 has higher priority For the $C=C$ at C3: - The double bond carbons bear substituents; assign priorities - Configuration at C3 is **E** (trans geometry) - Configuration at C2 is **R** (when $OH$ and $H$ are ignored in 3D) **Answer: (2R, 3E)-pent-3-en-2-ol → Option (1)** ✓ The compound has an $R$-stereocenter at C2 and an $E$-configured double bond at C3.