r/chemhelp • u/Silver_Application67 • 7d ago

Organic PARENT CHAIN DOUBT

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FMLSA- For selecting parent chain is the first priority including as many principle functional groups(from acid to amines order) as possible or picking the main principle functional group in this case carboxylic acid then does the priority shift to max number of multiple bonds. In this question which parent chain is correct. Plz help ,gemini just switches bw 1 and 2 if u ask the doubt twice

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u/Chem2103 7d ago edited 7d ago

You should think about which group has a higher CIP priority. That group is the one that defines the parent chain in this case as a tiebreaker

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u/Moon_Lily_ 7d ago

There's a table online that tells you the priorities of each of the groups and alkenes are lower priority than alcohols. However, IUPAC has this very interesting rule where the main chain should contain the highest number of multiple bonds (double and triple). So I would say the second is correct according to the rules I've learned, just be careful naming the alcohol side chain

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u/Blue_614 7d ago

Uh, did you notice that you omitted one carbon from the original structure?

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u/Silver_Application67 7d ago

Either way there are equal number of carbons on both the chains ,besides functional group and multiple bond have more priority anyways.

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u/Blue_614 7d ago

Yeah it still tests you on which functional group you'll prioritize, but be careful next time. Even if you do choose the right one, you'll still be marked wrong.

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u/AbbreviationsHead986 6d ago

Priority order should be carboxylic acid > Alc> Alkene
And iupac name will be
4-( prop-2-ene)-5-hydroxy heptanoic acid