Dimethylpentane:
The prefixes di-, tri-, tetra- etc. are employed for similar substituents, but the order within which they are written is still relies upon the alphabetical order of the substituents themselves (that is ignore the di-, tri-, tetra-, et cetera). For instance, the structure in below figure is termed as 5-ethyl-2,2-dimethyldecane and not 2,2-dimethyl-5-ethyldecane.
![1741_Dimethylpentane.png](https://www.expertsmind.com/CMSImages/1741_Dimethylpentane.png)
Figure: 2, 2-Dimethylpentane.
![2440_Dimethylpentane1.png](https://www.expertsmind.com/CMSImages/2440_Dimethylpentane1.png)
Diagram: 5-Ethyl-2, 2-dimethyldecane