See image — Alcohols Phenols and Ethers Chemistry Question

💡 Solution & Explanation

Step 1 – Identify the starting material. The starting material is a cyclopentanone with a stereogenic center at C2 bearing a –CO2Et group on a wedge bond (defined absolute configuration, a single enantiomer). Step 2 – Understand what LiAlH4 does. LiAlH4 reduces both the ketone (C=O at C1) and the ester (–CO2Et at C2) to give the corresponding alcohols: C1 ketone → C1–OH, and –CO2Et → –CH2OH at C2. Step 3 – Analyze stereochemical outcome at each center. • At C2: The configuration is already set (wedge bond in starting material). The reduction of the ester –CO2Et to –CH2OH does not break the C2–C bond; it converts the ester carbonyl to –CH2OH while the stereocenter at C2 retains its configuration. So C2 remains a single defined stereocenter. • At C1 (former ketone): LiAlH4 reduces the cyclopentanone to give a new stereocenter at C1. The hydride can attack from either face of the planar ketone, but the existing stereocenter at C2 creates a diastereotopic environment, meaning the two faces are not equivalent (facial selectivity is not necessarily 50:50, but more importantly the two outcomes give diastereomers, not enantiomers). Step 4 – Identify the nature of the product mixture. Because C2 is a fixed stereocenter (from the optically pure starting material) and C1 becomes a new stereocenter upon reduction, hydride attack on the two faces of C1 produces two products that differ at C1 but not at C2. These two products are diastereomers of each other. Step 5 – Eliminate other options. • (a) Racemic: A racemic mixture would require equal amounts of two enantiomers. Since C2 is fixed, the two products formed differ at C1 only and are diastereomers, not enantiomers. So the mixture is not racemic. • (c) Meso: A meso compound requires an internal plane of symmetry that makes the molecule achiral despite stereocenters. The cyclopentane ring with OH and CH2OH substituents does not possess the necessary internal symmetry for a meso compound here. • (d) Optically pure: Optically pure would mean a single stereoisomer is formed with 100% stereoselectivity at C1. LiAlH4 is not stereospecific enough to guarantee complete facial selectivity, and the question implies a mixture is obtained. • (b) Diastereomer: The reaction produces two products (cis and trans isomers of the 1-hydroxy-2-(hydroxymethyl)cyclopentane) that are diastereomers because they share the same configuration at C2 but differ at C1. Therefore, the correct answer is B.