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4-ethyl-2,2-dimethylhexane vs 2,2-dimethyl-4-ethylhexane

Posted: Tue Feb 28, 2017 3:01 pm
by Yiling Liu 1N
in the "Introduction to Organic Chemistry" workbook on page 8, the book names the alkane 4-ethyl-2,2-dimethylhexane.

it says "the substituents are placed alphabetically (ethyl then dimethyl)"

but doesn't the letter "d" come before the letter "e"?

Is 2,2-dimethyl-4-ethylhexane also an acceptable answer?

If not, why?

Re: 4-ethyl-2,2-dimethylhexane vs 2,2-dimethyl-4-ethylhexane

Posted: Tue Feb 28, 2017 4:08 pm
by Preston_Dang_1B
The order is based on the first letter of the individual substituents regardless of the prefix in front. In other words, for dimethyl, it is the "m" that is ordered and not the "d." Therefore, ethyl would be written before methyl in the naming of the compound rather than the other way around because of the "di" prefix in front of the methyl.

Hope this helps!

Re: 4-ethyl-2,2-dimethylhexane vs 2,2-dimethyl-4-ethylhexane

Posted: Wed Mar 01, 2017 4:24 pm
by samuelkharpatin2b
When naming compounds, you are supposed to ignore the prefix. That is, you disregard the "di-" in dimethylhexane and use the first letter "m" when taking into account alphabetical order. This is the same for all prefixes.