Question

trans-3, 6-Dimethyl oct-4-ene (A) exists in two diastereomers (I) and (II). The total number of stereoisomers for (A) is :

• A. 6
• B. 8
• C. 4
• D. 5

Answer 1

Answer: (A)

6

Two asymmetric C atoms with the same terminal group (n = number of asymmetric C atom and is even) Number of O. A. I. = $2^{n-1}$ = 2
Number of mcso forms = $2^{(n-2)/2}$ = I
Total optical isomers = 3
One double bond = 2 disteromers
$Totalstereoisomers=3\times 2=6$