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For the compound $\ce{CH3-CH(OH)-CH3}$ I propose two names: propan-2-ol and 1-methylethanol. Which is the correct name as per the IUPAC guidelines?

According to Organic Chemistry by Morrison and Boyd, the name is given as propan-2-ol. Why is 1-methylethanol not accepted?

andselisk
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Get_ Maths
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  • I am in prefer of the latter name to be correct by giving more priority to the functional group rather than number of carbons . – Get_ Maths Jan 31 '22 at 05:11
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    The Wikipedia does a pretty reasonable job of explaining this: https://en.wikipedia.org/wiki/IUPAC_nomenclature_of_organic_chemistry#Alcohols and https://en.wikipedia.org/wiki/IUPAC_nomenclature_of_organic_chemistry#Order_of_precedence_of_group – Buck Thorn Jan 31 '22 at 07:23
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    The name is derived from the longest carbon chain - in this case propyl. 1-Methyl ethanol is incorrect. – Waylander Jan 31 '22 at 08:37
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    As side note, chemistry.se's page resources for learning chemistry includes a dedicated section «References about Nomenclature», too. You might want to start reading the 4-page summary, or the brief guide; both illustrated and published open access as .pdf. – Buttonwood Jan 31 '22 at 08:55
  • "Confusion regarding Nomenclature" is a horrible title (it's not even a question — it's a complaint), and please don't use math mode where it makes no sense, e.g. for plain text. When citing third-party sources, make sure your citation is complete and unambiguous so that others don't have to guess your textbook's edition, year and page number your are referring to. – andselisk Jan 31 '22 at 16:07
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    @buttonwood As another side note, links to the guides can also be found when you click on the "nomenclature" tag and then on "Lern more …". I don't know if that's easier, though. – Loong Jan 31 '22 at 17:33
  • @Long Indeed, this is new for me. Perhaps because I did not use tag «nomenclature» as often as possible (homework for me). Briefly, I compared the two .pdf documents the tag points to (2015 vs 2020) with diffpdf and leave it with «their organization to present the material is different» assuming the rules by 2015 are those in the 2020 document. Because your name is seen frequently when answering these questions. possibly you know better. For a quick look on the 4-page summaries and access to all Color Books, I liked the link to the resource page. – Buttonwood Jan 31 '22 at 18:59
  • @Waylander , yeah that would be correct but there is also a rule that no matter of the longest carbon chain , the numbering should start from the carbon which is nearest to functional group . So we should start naming it from mid carbon as it's nearest to alcohol group . – Get_ Maths Feb 01 '22 at 03:02
  • Please reference this rule you to which you allude, Get_Maths. Perhaps you mean that 2-hexanol should not be named 5-hexanol. If so, then the lower number is secondary to the chain length. @Waylander – user55119 Feb 18 '22 at 16:15
  • No carbon chain can ever be 1-substituted with a carbon-based substituent, because that means the chain itself is one carbon longer than you originally said. – Curt F. Feb 19 '22 at 01:06

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