question_answer

How many diastereomeric pairs are possible in the given compound when COOH group in the given structure is replaced by \[C{{H}_{3}}\] group\[C{{H}_{3}}-\underset{\begin{smallmatrix}  | \\  OH \end{smallmatrix}}{\mathop{C}}\,H-\underset{\begin{smallmatrix}  | \\  OH \end{smallmatrix}}{\mathop{C}}\,H-COOH\]

A)  1                    

B)  2

C)  3                                

D)  4

Correct Answer: B

Solution :

\[C{{H}_{3}}-\underset{\begin{smallmatrix}  \,\,\,\,| \\  OH \end{smallmatrix}}{\mathop{C}}\,H-\underset{\begin{smallmatrix}  \,\,\,\,| \\  OH \end{smallmatrix}}{\mathop{C}}\,-C{{H}_{3}}\]\[={{2}^{2-1}}+{{2}^{2/2-1}}\,=2+1=3\]             (I)                         (II)                         (III)             I & II are diastereomeric pair I & III are diastereomeric pair II & III are enantiomeric pair.