Consider the thermal decomposition
`CH+_(3)CH_(2)underset(CH_(3))underset(|)(CH)-overset(+)N(CH_(3))_(3)OH^(-)overset(Delta)rarr`
Which of the following is the major product ?

Options

A. But-`1`-ene
B. cis-But-`2`-ene
C. trans-But-`2`-ene
D. A mixture of (2) and (3)

Answer

A

Explanation

Elimination proceeds by the removal of a `beta-H` as proton. Any factor that affects its ease of removal will affect the rate of reaction. When alternatives `beta-H's` are present, the one most readily removed as proton will decide the structure of the predominnating alkene product. Terminal `beta H's` are more acidic than internal `beta H's`. Therefore, but-`1`-ene is the major product.

We can predictd the major product using Hofmann's rule.