IUPAC name of the some alkenes are given below.
Find out the correct stability order.

$$\textbf{A.}$$ 2-Methylbut-2-ene

$$\textbf{B.}$$ $$\textit{cis}$$-But-2-ene

$$\textbf{C.}$$ 2,3-Dimethylbut-2-ene

$$\textbf{D.}$$ Prop-1-ene

Choose the correct answer from the options given below:

The stability of alkenes is largely governed by hyperconjugation. According to NCERT, greater the number of (\alpha)-hydrogens attached to the carbon atoms adjacent to the double bond, greater is the number of hyperconjugative structures and hence greater is the stability of the alkene.

For 2-methylbut-2-ene ((CH_3-C(CH_3)=CH-CH_3)), the double bond is adjacent to three methyl groups. Therefore, the total number of (\alpha)-hydrogens is

$$3+3+3=9.$$

For cis-but-2-ene ((CH_3-CH=CH-CH_3)), the double bond is adjacent to two methyl groups, giving

$$3+3=6$$

(\alpha)-hydrogens.

For 2,3-dimethylbut-2-ene (((CH_3)_2C=C(CH_3)_2)), the double bond is adjacent to four methyl groups. Hence, the number of (\alpha)-hydrogens is

$$3+3+3+3=12.$$

For prop-1-ene ((CH_3-CH=CH_2)), the double bond is adjacent to only one methyl group, so the number of (\alpha)-hydrogens is

$$3.$$

Since alkene stability increases with the number of (\alpha)-hydrogens, the order of stability is

$$C>A>B>D.$$

Hence, the correct order is C > A > B > D.