Question

Give the major product of the following reaction:
3, 3- dimethyl-1-butene $+ HCl \to Major$
A. 2-chloro-3,3-dimethyl butane
B. 2-chloro-2,3-dimethyl butane
C. 1,2- dichloro-3,3-dimethylbutane
D. 1-chloro-3,3-dimethylbutane

Answer 1

Organic compounds are the compounds which in solid, liquid, and gaseous state contain carbon in its molecule. A large number of organic compounds are there and a systematic classification is required. Organic compounds are classified as open-chain (acyclic), closed chain (cyclic). Open chain is classified into two types: straight-chain and branched-chain. The closed chain is classified into two types: Homocyclic compounds and Heterocyclic compounds. Homocyclic compounds are classified into two types: Alicyclic compounds and Aromatic compounds.

Complete step by step answer:
When 3, 3- dimethyl-1-butene reacts with HCl it gives 2-chloro-2, 3-dimethyl butane as the major product. The reaction along with the mechanism is written below:

Mechanism:
Step 1: In this step, the double bond in 3, 3- dimethyl-1-butene breaks and it forms a secondary carbocation, and the ${H^ + }$ ion of HCl gets added to the negative carbon.

Step 2: In this step one methyl group gets shifted to secondary carbocation to form tertiary carbocation which is the most stable carbocation.

Step 3: The $C{l^ - }$ ion will be added to the tertiary carbocation to form the major product 2-chloro-2, 3-dimethyl butane.

Therefore the major product is 2-chloro-2, 3-dimethyl butane.

Hence, the correct option is B.

Note: When a group X, having electronegativity higher than carbon is attached to it, $\left( {C - X} \right)$ bond breaks heterolytically. The shared pair of electrons is given to the atom other than the carbon. Thus, the carbon atom acquires a positive charge. It has only six electrons in its valence shell. Such a type of ion of carbon is known as carbocation or carbonium ion. The positively charged ion of the carbocation is $s{p^2}$ hybridized.