Question

What is the action of following reagents- (i) Bromine (ii) Cold and dilute allkaline $KMn{O}_4$ on-

(i) but-$1$-ene and

(ii) but-$2$-ene?

Answer 1

$i)withbromine$

Treatment of an alkene with $B{r}_2$ in chlorinated solvent lead to the formation of dibromo alkenes. See the figure 1.

$ii)withcoldanddilKMn{O}_4$

Treatment of an alkene with cold & dil $KMn{O}_4$ lead to the formation vicinal diols, i.e. mild oxidation takes place. See the figure 2.