See image — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

# Solution: Stereoisomers of $H_3C(HO)HC'CH=CH''CH(OH)CH_3$ (X) ## Structure Analysis The molecule has: - **2 chiral centers**: C' (with OH) and C'' (with OH) - **1 double bond** (C'=C'') with geometric isomerism possible ## Counting Stereoisomers **Step 1:** Each chiral center can exist in R or S configuration - C' chiral center: 2 possibilities - C'' chiral center: 2 possibilities **Step 2:** The double bond can have: - **cis** configuration (both OH groups on same side) - **trans** configuration (OH groups on opposite sides) **Step 3:** Calculate total stereoisomers $$\text{Total stereoisomers} = 2^{\text{(chiral centers)}} \times 2^{\text{(double bonds)}}$$ $$= 2 \times 2 \times 2 = 8$$ However, examining the specific structure with the OH groups on adjacent sp² carbons in the double bond: - The **cis** form yields 2 enantiomers - The **trans** form yields 2 enantiomers - Due to symmetry considerations in this particular case, **total = 6 distinct stereoisomers** ## Verification of Other Options - **(B)** False: Diastereomers = total stereoisomers − enantiomeric pairs = more than 3 - **(C)** False: If trans, enantiomers = 2 (one enantiomeric pair), not 4 - **(D)** False: If cis, enantiomers = 2 (one enantiomeric pair), not 2 separate ones **Answer: (A) is correct** — 6 total stereoisomers possible.