IUPAC Naming. Which one is correct?

Question

(2E,4E)-3-ethyl-6-ethynyl-7-methyldeca-2,4-dienenitrile

I have named this according to the numbering shown as
3-ethyl-6-(1-methylbutyl) oct-2,4-diene-7-ynenitrile.
But my book's answer key says
3-ethyl-6-ethynyl-7-methyl deca-2,4-dienenitrile
This means it has taken the triple bond as a side chain. But IUPAC rule says that the chain with maximum number of double and triple bond is taken even if it is shorter than a chain with lesser double or triple bonds. Which answer is correct and why, for the given example?

“But IUPAC rule says that the chain with maximum number of double and triple bond is taken even if it is shorter than a chain with lesser double or triple bonds.” Such a rule had been given in old recommendations that are now obsolete. According to current IUPAC recommendations, the first criterion to be considered in choosing a preferred parent acyclic chain is the length of the chain; unsaturation is now the second criterion. — , Dec 03 '17 at 15:44
Related: How do you name an alkene using IUPAC rules if the longest carbon chain in this alkene does not include the double bond? — , Dec 03 '17 at 15:45

score 1 · Answer 1 · answered Dec 04 '17 at 11:04

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As Loong said, the up-to-date IUPAC recommendation stipulates that the chain with the longest continuous chain of carbon atoms should be the parent chain. For this reason, I would agree with your textbook's answer.

answered Dec 04 '17 at 11:04

Elizabeth T

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Can you back that up with some more details and cite the rules necessary to understand it. Otherwise it is just a restatement of a comment and not necessarily a real answer. – Martin - マーチン Dec 05 '17 at 05:32

IUPAC Naming. Which one is correct?

1 Answers1