Question

Which of the given molecules of dichloro cyclohexane is meso?

• A. cis-1,2; cis-1,3; cis-1,4
• B. 1,1; cis-1,2; cis-1,3; cis-1,4; trans-1,4
• C. 1,1; cis-1,2; cis-1,3
• D. cis-1,2; cis-1,3

Answer 1

Answer: (B)

1,1; cis-1,2; cis-1,3; cis-1,4; trans-1,4

Possibility of two chlorine atoms on cyclohexane are 1,1 ; 1,2 ; 1,3 ; 1,4.

1 ,1 is not chiral so meso compound.

1,2 and 1,3 dichloro cyclohexane has two stereoisomers cis and trans.

trans isomer forms non super imposable mirror images Hence not meso compound.

1,4 dichloro cyclohexane forms superposable mirror image in any of the way so both are meso compounds.

1,1 ; cis 1,2 ; cis 1,3 ; cis 1,4 ; trans 1,2