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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: shalikadm on June 04, 2012, 04:18:58 AM

Title: IUPAC nomenclature problem
Post by: shalikadm on June 04, 2012, 04:18:58 AM: I'm using a software called MarvinSketch 5.9.4 to check my nomenclature answers...It seems accurate..But I found something that I cant understand.Here is the structure I inserted and got 2-ethenyl-formylpentanamide but I think it must be 2-formyl-2-propylbut-3-enamide...
1.parent hydrocarbon chain must have maximum number of double bonds..
2.then :rarrow:the maximum number of C atoms
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fs16.postimage.org%2F9af598zsl%2Fimage.png&hash=3b25be720ba8286fdc47cb51b65a3dbb96a9ab6e)
EDIT:now seems to be not much accurate getting this,
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fs13.postimage.org%2F85yv93p5z%2FUntitled.png&hash=0ff60f56a463ee260870007fcff7d36c02a94030)
my suggestion : 4-bromo-3-propylpent-4-en-1-ol
Title: Re: IUPAC nomenclature problem
Post by: discodermolide on June 04, 2012, 05:12:48 AM: Quote from: shalikadm on June 04, 2012, 04:18:58 AM
I'm using a software called MarvinSketch 5.9.4 to check my nomenclature answers...It seems accurate..But I found something that I cant understand.Here is the structure I inserted and got 2-ethenyl-formylpentanamide but I think it must be 2-formyl-2-propylbut-3-enamide...
1.parent hydrocarbon chain must have maximum number of double bonds..
2.then :rarrow:the maximum number of C atoms
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fs16.postimage.org%2F9af598zsl%2Fimage.png&hash=3b25be720ba8286fdc47cb51b65a3dbb96a9ab6e)
EDIT:now seems to be not much accurate getting this,
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fs13.postimage.org%2F85yv93p5z%2FUntitled.png&hash=0ff60f56a463ee260870007fcff7d36c02a94030)
my suggestion : 4-bromo-3-propylpent-4-en-1-ol

Here are the names as produced by ChemDraw. Good luck!
Title: Re: IUPAC nomenclature problem
Post by: shalikadm on June 04, 2012, 05:23:44 AM: sorry..who is corect then ?....me or marvinsketch or chemdraw ?
Title: Re: IUPAC nomenclature problem
Post by: discodermolide on June 04, 2012, 05:27:51 AM: Quote from: shalikadm on June 04, 2012, 05:23:44 AM
sorry..who is corect then ?....me or marvinsketch or chemdraw ?

I'd put my money on ChemDraw although others here may disagree.
Title: Re: IUPAC nomenclature problem
Post by: shalikadm on June 04, 2012, 05:32:33 AM: Quote from: discodermolide on June 04, 2012, 05:27:51 AM
Quote from: shalikadm on June 04, 2012, 05:23:44 AM
sorry..who is corect then ?....me or marvinsketch or chemdraw ?

I'd put my money on ChemDraw although others here may disagree.

so there are others who disagree with ChemDraw's nomenclature ?
Title: Re: IUPAC nomenclature problem
Post by: shalikadm on June 04, 2012, 05:40:40 AM: I'm eager to know the correct one ! ;)
here's another one....
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fs18.postimage.org%2Fcce8vlw2x%2FUntitled.png&hash=5e2eeab97c303d5d0f9722188b440a7ac27c5f62)
my guess : methyl 6-bromo-3-propylpent-3-enoate
Title: Re: IUPAC nomenclature problem
Post by: shalikadm on June 04, 2012, 06:03:39 AM: I think mervinsketch is not obeying rules...I found that it selects the longest C chain without thinking about double or triple bonds..am I correct ?
Title: Re: IUPAC nomenclature problem
Post by: discodermolide on June 04, 2012, 06:17:43 AM: Quote from: shalikadm on June 04, 2012, 05:40:40 AM
I'm eager to know the correct one ! ;)
here's another one....
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fs18.postimage.org%2Fcce8vlw2x%2FUntitled.png&hash=5e2eeab97c303d5d0f9722188b440a7ac27c5f62)
my guess : methyl 6-bromo-3-propylpent-3-enoate

You did not specify the geometry of the double bond. here is a picture of what I think you meant.
Title: Re: IUPAC nomenclature problem
Post by: shalikadm on June 04, 2012, 07:00:48 AM: I have no understanding about that spiral thing..
any way this structure was taken from a book and it was printed as,
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fs15.postimage.org%2Fiasip367f%2FUntitled.png&hash=46d26b79fcf0080718f6b8e6a65b289a29d96b60)
There was nothing describing the geometry.
Title: Re: IUPAC nomenclature problem
Post by: sjb on June 04, 2012, 07:39:57 AM: Quote from: shalikadm on June 04, 2012, 07:00:48 AM
I have no understanding about that spiral thing..
any way this structure was taken from a book and it was printed as,
(https://www.chemicalforums.com/proxy.php?request=http%3A%2F%2Fs15.postimage.org%2Fiasip367f%2FUntitled.png&hash=46d26b79fcf0080718f6b8e6a65b289a29d96b60)
There was nothing describing the geometry.

"That spiral thing" is just a means of showing undefined double bond geometry. I wouldn't want to guess if the structure you have shown is cis or trans.
Title: Re: IUPAC nomenclature problem
Post by: orgopete on June 04, 2012, 05:27:01 PM: Quote from: shalikadm on June 04, 2012, 05:23:44 AM
sorry..who is corect then ?....me or marvinsketch or chemdraw ?

The Marvinsketch and ChemDraw names are the same, so I would go with them. The difference is ChemDraw uses the common variants of substituents, vinyl rather than ethenyl or t-butyl rather than 1,1-dimethylethyl.