Chemistry - STEREO ISOMERISM Question with Solution | TestHub
For each of the following compounds, identify any centers of chirality, and calculate the number of possible optical isomers :
(a) 
Glyceraldehyde
(b)
Arabinose (open chain)
(c)
Glucose (open chain)
Options:
Answer:
Solution:
(a) Glyceraldehyde: Only the middle carbon (bearing H, OH, CHO, and CH₂OH) is a chirality center. Thus, there is 1 chirality center, leading to optical isomers.
(b) Arabinose (open chain): C₂, C₃, and C₄ each bear four different groups, making them chirality centers. Thus, there are 3 chirality centers, leading to optical isomers.
(c) Glucose (open chain): C₂, C₃, C₄, and C₅ are chirality centers. Thus, there are 4 chirality centers, leading to optical isomers. The end groups, CHO and CH₂OH, are not stereogenic. Since the ends are unlike, no meso compensation is possible.
Ans. (D) (a) 1 chirality center, isomers; (b) 3 chirality centers, isomers; (c) 4 chirality centers, isomers.
