Question

How many stereoisomers does this molecule have? $CH_3CH = CHCH_2CHBrCH_3$

• A. 4
• B. 6
• C. 8
• D. 2

Answer 1

Answer: (A)

4

Answer 2

C$^{\bullet}$ = asymmetric carbon
Number of optical isomers = 2$^n$
where, n = number of asymmetric carbon atoms
\hspace20mm 2^1=2
Number of geometrical isomers = $2^n$
where, n = number of double bonds = $2^1 = 2$
Hence, total number of stereoisomers = Total
optical isomers 4- Total geometrical isomers
$=2+2=4$