What is the correct structure of 2,2-dimethylbutane?

2,2-Dimethylbutane has a specific structure characterized by its branched alkane configuration. The name indicates that there are two methyl groups attached to the second carbon of a butane chain.

In the structure of 2,2-dimethylbutane, the longest continuous carbon chain is four carbons long (the butane part). The numbering of the carbon atoms starts from the end closest to a substituent, which in this case are the two methyl groups. Thus, the second carbon (C-2) will have two –CH3 groups attached to it, while the other carbon atoms are not substituted.

The correct structure reflects this arrangement where the central carbon (C-2) has two methyl groups branching off, making it a 2,2-substituted branch. As represented, the structure shows two methyl groups on the second carbon of a straight chain of four carbon atoms, consistent with the naming and satisfying the saturation of carbon with hydrogens required for a fully saturated alkane.

Other structures do not fit this description. For instance, options that suggest other placements of the methyl groups or additional branching fail to accurately represent the exact position needed as indicated by the name '2,2-dimethyl