Question

When trans-2-butene is reacted with $B{{r}_{2}}$ then product is formed:
A. Racemic-2,3-dibromobutane
B. Meso-2,3-dibromobutane
C. d-2,3-dibromobutane
D. l-2,3-dibromobutane

Answer 1

Hint: Alkenes generally undergo additional chemical reactions with other chemicals due to the presence of a high number of electrons with them. The formation of the major product is going to depend on the presence of the substituents in the alkenes.

Complete answer:
- In the question it is asked to find the product when trans-2-butene is going to react with bromine among the given options.
- First, we should know the structure of the trans-2-butene and it is as follows.

- Now, we have to write the chemical reaction between trans-2-butene and bromine and it is as follows.

- In the above chemical reaction, we can see that the bromine is going to react on the double bonded carbon in two different directions.
- When the bromine is going to react with double bonded carbon from the above side and from the below side the formed products are d and l-form.
- Means we are going to get a meso compound when bromine is going to react with trans-2-butene.

Therefore, the correct option is B, Meso-2,3-dibromo butane.

Note:
The formation of the products in the additional chemical reactions on the highly substituted alkenes is going to depend on the reagent which is going to be involved in the chemical reaction. If the reagent is homodimer, then the product will be meso in nature.