Question

What alkene is the major product formed from each alkyl halide in an E1 reaction?

a.

b.

c.

Short answer

The major product formed in an E1 reaction is:

Step-by-step solution

Definition of E1 reaction

The 2-steps elimination reaction where the formation of the carbocation is the intermediate step is known as the E1 reaction. A proton and a leaving group get removed from the system. In this case, the rate depends only on the substrate.

Stability of the carbocation

E1 is favorable in those cases where the carbocation formed in the intermediate step is stable.

Stability based on substitution

The major product will be considered in those compounds where more number of substituted alkenes are formed.

With an increase in the number of substituted alkyl groups, more +I effect will be shown by them. As a result, the stability of the product formed increases.

Hence, the major product formed in an E1 reaction is:

Representation of E1 product from compound a

Representation of E1 product from compound b

Representation of E1 product from compound c