Question

Question: Identify the starting material in each reaction.

a.

b.

Short answer

Answer

a.

b.

Step-by-step solution

Degree of unsaturation

The degree of unsaturation is used to find out the unsaturation in the compound. It is given by the formula

$\mathrm{Degree}\mathrm{of}\mathrm{Unsaturation}=\frac{2\mathrm{C}+2+\mathrm{N}-\mathrm{X}-\mathrm{H}}{2}$

Here,

• C is carbon
• N is nitrogen
• X is halogen
• H is hydrogen

Identification of reactants in a and b

a. The given compound is C₁₀H₁₈. Substitute the values in the formula.

$$\begin{gathered} \mathrm{Degree}\mathrm{of}\mathrm{unsaturation}=\frac{2\times 10+5-18}{} \\ =\frac{4}{2} \\ =2 \end{gathered}$$

Thus, the degree of unsaturation is 2. The starting material is identified as follows:

Starting material in a

b.The given compound is C₁₀H₁₆. Substitute the values in the formula.

$$\begin{gathered} \mathrm{Degree}\mathrm{of}\mathrm{reaction}=\frac{2\times 10+2-16}{2} \\ =\frac{6}{2} \\ =3. \end{gathered}$$

Thus, the degree of unsaturation is 3. The starting material is identified as follows:

Starting material in b