For each of the following compounds, identify the centres of chirality and calculate the number of possible optical isomers :
(a) 3-chlorobutan-2-ol
(b) Glucose (open chain)
(c) Menthol

Question

For each of the following compounds, identify the centres of chirality and calculate the number of possible optical isomers : (a) 3-chlorobutan-2-ol (b) Glucose (open chain) (c) Menthol

TestHub · Accepted Answer

Ans. (A) (a) chiral centres = 2, optical isomers = 2² = 4; (b) chiral centres = 4, optical isomers = 2⁴ = 16; (c) chiral centres = 3, optical isomers = 2³ = 8.

Sol. (a) 3-Chlorobutan-2-ol: C-2 (H, OH, CH₃, CHClCH₃) and C-3 (H, Cl, CH₃, CH(OH)CH₃) are both stereogenic and the two ends differ, so 2² = 4. (b) Open-chain glucose, CH₂OH-(CHOH)₄-CHO: the four CHOH carbons are stereogenic, so 2⁴ = 16. (c) Menthol: the carbons bearing OH, isopropyl and CH₃ on the ring are stereogenic, so 2³ = 8.

Chemistry - STEREO ISOMERISM Question with Solution | TestHub

Options:

Doubts & Discussion