Naming Compounds Clarification

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Jacqueline Lee
Posts: 21
Joined: Fri Sep 25, 2015 3:00 am

Naming Compounds Clarification

Postby Jacqueline Lee » Tue Feb 23, 2016 5:27 pm

For the first quiz 3 prep, the answer for question 2 listed the name for CH3CH(CH3)CH(CH2CH3)C(CH3)3 as 2,2,4-trimethyl-3-ethylpentane.

Why isn't it 3-ethyl-2,2,4-trimethyl-pentane, having ethyl come before methyl?

Also if there are multiple substituents, would the numbers change so the first substituent listed will have the lowest number?

Albert Chong_1L
Posts: 77
Joined: Fri Sep 25, 2015 3:00 am

Re: Naming Compounds Clarification

Postby Albert Chong_1L » Tue Feb 23, 2016 6:04 pm

I agree with your first question that the ordering seems strange.

To answer your second question, the substituent listed first is always given the lower number if equivalent numbering is possible. However, if lower numbers in general can be obtained by giving the first substituent a higher number than substituent(s) after it, you give the higher number to the first substituent.

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