3
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molecule

What is this compound's IUPAC name?

1) 2-phenyloctane.
2) octan-2-ylbenzene.

Is using phenyl correct or is taking benzene as the base correct?

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11
  • $\begingroup$ I did the following searches to find that if aliphatic chain has more than 6 carbon atoms then it prefers using phenyl : m.wolframalpha.com/input/?i=2-phenylpentane&x=0&y=0 & m.wolframalpha.com/input/?i=2-phenylhexane&x=0&y=0 . Also this says so too. So is it correct ? $\endgroup$
    – pikachu
    Mar 9, 2015 at 12:51
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    $\begingroup$ @MARamezani Not more than two links $\endgroup$
    – pikachu
    Mar 9, 2015 at 12:58
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    $\begingroup$ @pikachu Yes, both ‘octan-2-ylbenzene’ and ‘2-phenyloctane’ are correct; ‘octan-2-ylbenzene’ is the preferred IUPAC name. $\endgroup$
    – user7951
    Mar 9, 2015 at 13:02
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    $\begingroup$ @pikachu That site is not necessarily wrong, since according to current IUPAC recommendations (2013), “the context may favor (…) the chain, so that (…) an unsaturated acyclic structure may be recognized, or the one chosen has the greater number of skeletal atoms (…) in the principal chain of the acyclic structure.” However, the approach for the preferred IUPAC name (PIN) prefers the choice of a ring over a chain in systems composed of cyclic and acyclic hydrocarbons. $\endgroup$
    – user7951
    Mar 20, 2015 at 17:22
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    $\begingroup$ @pikachu The old IUPAC rule (from 1979) actually was: “Choice between these methods is made according to the more appropriate of the following principles: (…) (b) treatment of a smaller of structure as a substituent into a larger. (…) In accordance with the principle (b) (…), a hydrocarbon containing a small cyclic nucleus attached to a long chain is generally named as a derivative of the acyclic hydrocarbon; (…)” $\endgroup$
    – user7951
    Mar 20, 2015 at 17:23

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