Question

The IUPAC name of the following compound is?

• A. 5-Ethyl-7-(1, 2-dimethylpropyl)undecane
• B. 5-(1,2-Dimethylpropyl)-7-ethylundecane
• C. 5-(1-Propylpropyl)-7-ethylundecane
• D. None of these

Answer 1

The correct option is B

5-(1,2-Dimethylpropyl)-7-ethylundecane

Parent chain and numbering so that a more substituted substituent will get the least number.

Parent chain

11 carbons$\Rightarrow$ Word root$\Rightarrow$undec

Single bond$\Rightarrow$ suffix$\Rightarrow$ ane

substituent at $C_{5}and{C}_7$

Therefore,

(b) 5-(1,2-Dimethylpropyl)-7-ethylundecane

Here in the case of the substituent, the d in dimethyl is considered.

Thus dimethyl, which is enclosed in the parentheses precedes ethyl alphabetically.