Question on number 27?

[Grace_Stevenson_1A]

Wouldn't 27 not be a correct name because you give priority to the functional groups?

[Calvin Huang 3D]

The naming is correct. Ketone is the functional group here and is given priority in that its suffix is attached onto the parent chain (in this case propane) at the 3rd carbon. You state the non functional groups first which is why the 2-dimethyl comes before the functional group. You will have 2 methyl groups attached to the 2nd carbon.

[Mihika Sridhar 3H]

I think Grace is asking why the ketone functional group has a lower carbon number than the methyl groups since we've learned that functional groups have the highest priority in carbon numbering. Why isn't it 4-dimethyl-3-pentanone instead?