Question

Statement 1: Addition of $B{r}_2$ to cis-but-2-ene is stereoselective.
Statement 2: $S_{N}2$ reactions are stereospecific as well as stereoselective.

• A. If both Statement 1 and Statement 2 are true and the statement 2 is the correct explanation o f the statement 1.
• B. If both Statement 1 and Statement 2 are true but statement 2 is not the correct explanation of the statement 1.
• C. If Statement 1 is true but Statement 2 is false.
• D. If Statement 1 is false but Statement 2 is true.

Answer 1

Answer: (B)

A reaction is said to be stereo selective if a particular stereoisomer can give two or more stereoisomeric products but gives one of them in greater amount than the other or even to the exclusion of the other. So, addition of $B{r}_2$ to $cis-but-2-ene$ is stereoselective since it gives only $(\pm )$ 2, 3-dibromobutane.