Naming with iso- and neo-

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404757006
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Joined: Wed Sep 21, 2016 3:00 pm

Naming with iso- and neo-

Postby 404757006 » Mon Mar 06, 2017 10:38 pm

it wasnt very clear to me when iso- and neo- prefixes are used in naming can someone clear that up for me?

Cliff Danza 3F
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Re: Naming with iso- and neo-

Postby Cliff Danza 3F » Mon Mar 06, 2017 11:09 pm

Iso- and Neo- are used in common naming for the shape of the structure, followed by the appropriate carbon alkane/alkene/alkyne group name (like -hexane or -propane), counting all the carbon atoms.

Iso- and Neo- are used in IUPAC naming only for the substituents. For example, if there was a decane main group with a propyl group attached to it with that "Y" structure Iso- describes, then the IUPAC name could be: 4-Isopropyl-Decane (this is #1 in Quiz 3 Prep).

Oyindamola Akinnusi 2A
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Re: Naming with iso- and neo-

Postby Oyindamola Akinnusi 2A » Mon Mar 06, 2017 11:28 pm

When naming with iso- neo-, if the organic compound consists of more than three methyl groups then it is considered neo-right? And when it consists of less than three is its considered iso-

404757006
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Joined: Wed Sep 21, 2016 3:00 pm

Re: Naming with iso- and neo-

Postby 404757006 » Mon Mar 06, 2017 11:44 pm

Thank you for the clarification. This helps a lot.

Christian Hardoy 3F
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Joined: Fri Jul 15, 2016 3:00 am

Re: Naming with iso- and neo-

Postby Christian Hardoy 3F » Tue Mar 07, 2017 1:10 am

The prefixes iso- and neo- aren't the paid attention to when alphabetizing, correct? I ask because problem 1.16 in the o-chem homework says that the name for a structure is 2-isopropyl-1,1-dimethylcyclopentane when I got 1,1-dimethyl-2-isopropylcyclopentane. Is the textbooks answer correct because the prefixes somehow influence the alphebetization or is there something I am missing?

hfrazer1B
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Re: Naming with iso- and neo-

Postby hfrazer1B » Tue Mar 07, 2017 2:12 am

Thank you for your answer!!

stephanieyang_3F
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Re: Naming with iso- and neo-

Postby stephanieyang_3F » Tue Mar 07, 2017 9:03 am

Oyindamola, yes, iso is specifcally for (CH3)2CH-- while neo is specifically for (CH3)3C--.

Christian, you have to consider them into alphabetizing. For all other prefixes (like number prefixes) you don't take them into account. That's why for 1.16 isopropyl comes before dimethyl.

704647747
Posts: 28
Joined: Fri Sep 25, 2015 3:00 am

Re: Naming with iso- and neo-

Postby 704647747 » Tue Mar 07, 2017 10:44 am

I'm still having a hard time understanding the difference between neo- and tert- substituents... can someone help explain? thank you!

stephanieyang_3F
Posts: 62
Joined: Wed Sep 21, 2016 2:55 pm

Re: Naming with iso- and neo-

Postby stephanieyang_3F » Sat Mar 11, 2017 8:31 am

This is something Dr. Lavelle posted on another thread. Thought it was pretty helpful:
http://web.chem.ucla.edu/~harding/IGOC/ ... _name.html


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