Naming Organic Compounds

[MedPR]

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My organic class wasn't very heavy on naming, so I'm not too comfortable with it beyond alkenes/cyclic structures. I know the functional groups well enough to recognize them immediately, but I don't know how to name things.

Can someone name the following for me. These are from TBR chapter 2, number 25.

1. CH2CH3COOH
2. H3COCOCH3
3. H3CH2COCOH
4. cyclopentane with carbon 1 and carbon 3 each replaced with an Oxygen.

 

[Erythropoietin]

My organic class wasn't very heavy on naming, so I'm not too comfortable with it beyond alkenes/cyclic structures. I know the functional groups well enough to recognize them immediately, but I don't know how to name things.

Can someone name the following for me. These are from TBR chapter 2, number 25.

1. CH2CH3COOH
2. H3COCOCH3
3. H3CH2COCOH
4. cyclopentane with carbon 1 and carbon 3 each replaced with an Oxygen.

1. propanoic acid
2. methyl ethanoate
3. ethyl formate
4. tetrahydrofuran

 

[MedPR]

1. propanoic acid
2. methyl ethanoate
3. ethyl formate
4. tetrahydrofuran

Thanks 🙂

I thought tetrahydrofuran only had 1 oxygen? http://en.wikipedia.org/wiki/File:Tetrahydrofuran.png

 

[Ssina]

I suck at nomenclature also, but so far has never missed any of the questions simply through POE... so I wouldn't worry about it too much, if you know the functional groups and very broad ideas about naming, you can easily eliminate the wrong choices.

 

[Erythropoietin]

oh my bad, that's 1,3-dioxolane (or 1,3-dioxacyclopentane).. which ever you like

 

[MedPR]

I suck at nomenclature also, but so far has never missed any of the questions simply through POE... so I wouldn't worry about it too much, if you know the functional groups and very broad ideas about naming, you can easily eliminate the wrong choices.

Well there was a question where the two answers I didn't rule out were methylpropanoate and ethylethanoate. I didn't know what they looked like, so I couldn't determine which one was better.

More specifically, I didn't know if methyl propanoate had the methyl group alpha, or the propane alpha.

 

[MT Headed]

Sometimes it can be faster to solve these backwards.

Methyl propanoate has methyl as an adjective and propane as a noun.

Draw a propane. Make it propanoate by converting a terminal carbon into a COOH group. Now make it a methyl by replacing the -OH group with a -OCH3.

 

[MedPR]

Sometimes it can be faster to solve these backwards.

Methyl propanoate has methyl as an adjective and propane as a noun.

Draw a propane. Make it propanoate by converting a terminal carbon into a COOH group. Now make it a methyl by replacing the -OH group with a -OCH3.

That only works if you know what "propanoate" is though. I need to find some quick guide to naming.

 

[Ssina]

yeah I know, TBR is super picky (which is good I guess, in case, we get something super tricky on the test), but usually you can eliminate 2 answers easily, one way off and another having the wrong carbon count... I guess I should do a little bit more practice, specially with esters or amide, as to where the pre/suffix/etc. will attach also... it wouldn't hurt!

 

[MedPR]

yeah I know, TBR is super picky (which is good I guess, in case, we get something super tricky on the test), but usually you can eliminate 2 answers easily, one way off and another having the wrong carbon count... I guess I should do a little bit more practice, specially with esters or amide, as to where the pre/suffix/etc. will attach also... it wouldn't hurt!

Yea, on most of those IR/NMR questions you can rule out something based on the number of carbons, oxygens, or degrees of unsaturation. The problem is that the ones you can't rule out are usually a little difficult to distinguish.

 

[MT Headed]

Propanoate- the 'oate' means it is a modification of propanoic acid; it doesn't have that final H of the COOH group.

Propanoic acid- the 'oic acid' means it is the acid (COOH) version of propane.

This would be covered in the beginning of the textbook chapter on carboxylic acids. I think it was my chapter 20.

 

[MedPR]

Propanoate- the 'oate' means it is a modification of propanoic acid; it doesn't have that final H of the COOH group.

Propanoic acid- the 'oic acid' means it is the acid (COOH) version of propane.

This would be covered in the beginning of the textbook chapter on carboxylic acids. I think it was my chapter 20.

Thanks.

I've actually learned a good bit of naming from doing TBR passages. For instance, a question about identifying a C4H8O2. Answer choices were an alcohol, ketone, aldehyde, and methylpropanoate. The context taught me what the ester names look like.

Even though it's difficult, annoying, and often poorly worded, I'm really liking TBR.

 

[Erythropoietin]

Thanks.

I've actually learned a good bit of naming from doing TBR passages. For instance, a question about identifying a C4H8O2. Answer choices were an alcohol, ketone, aldehyde, and methylpropanoate. The context taught me what the ester names look like.

Even though it's difficult, annoying, and often poorly worded, I'm really liking TBR.

methanoate
ethanoate
propanoate
No need for a guide, everything is inside the naming itself

 

[MedPR]

methanoate
ethanoate
propanoate
No need for a guide, everything is inside the naming itself

Yea I think I have it now.

So if the methyl group in methylpropanoate was replaced with an n-pentyl group, what would it be named? I would assume the propanoate stays, but I'm not sure since the pentyl chain is longer..?

 

[Ssina]

since the C=O bond is still bonded to the propane, that won't change... propanoate, and you just change the OCH3 with n-pentylO.... n-pentyl propanoate

 

[Ssina]

personally, I get confused with naming amides, but here they do a good job, in case you want to check it out
http://dl.clackamas.cc.or.us/ch106-05/nomencla1.htm