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Topic: [order of supstiuents naming alcohols] IUPAC names  (Read 3925 times)

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Offline jiujitsu123

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[order of supstiuents naming alcohols] IUPAC names
« on: January 29, 2007, 11:57:52 AM »
when naming the substituents is it in alphabetical order???

Offline english

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Re: [order of supstiuents naming alcohols] IUPAC names
« Reply #1 on: January 29, 2007, 03:34:32 PM »
Always.  Lower numbers do not necessarily go with what comes first alphabetically.  If there is a tie between two groups and the same number, then the alphabetically-ordered group gets the lower number.

—OH always gets the lowest number.

In general the priorities are thus:

C=O > OH > NH2 > alkene ~ alkyne

Carbonyls receive priority over alcohols; alcohols receive priority over amines; and amines receive priority over alkenes, which receive about the same priority as alkynes. 

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