Organic naming rules
This presentation is the property of its rightful owner.
Sponsored Links
1 / 68

Organic Naming Rules PowerPoint PPT Presentation


  • 106 Views
  • Uploaded on
  • Presentation posted in: General

Organic Naming Rules. AP Chemistry 439. For complete Rules go to: http://www.acdlabs.com/iupac/nomenclature/. Organic Compounds. Consist of mainly four elements C arbon H ydrogen O xygen N itrogen. Why Do We Need a Separate Set of Rules?. Examine some typical organic compounds CH 4

Download Presentation

Organic Naming Rules

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Organic naming rules

Organic Naming Rules

AP Chemistry 439

For complete Rules go to:

http://www.acdlabs.com/iupac/nomenclature/


Organic compounds

Organic Compounds

  • Consist of mainly four elements

  • Carbon

  • Hydrogen

  • Oxygen

  • Nitrogen


Why do we need a separate set of rules

Why Do We Need a Separate Set of Rules?

  • Examine some typical organic compounds

  • CH4

  • C2H6

  • Name these using typical covalent rules

Carbon tetrahydride

Dicarbon hexahydride


Organic naming rules

So?

  • That wasn’t so bad, right?

  • How about these:

  • C4H10

  • C5H12

  • See my point?

Tetracarbon decahydride

Pentacarbon ??? hydride


Isomers

H

H

C

H

H

H

H

H

H

H

H

C

C

C

C

H

H

C

C

C

H

H

H

H

H

H

H

H

Isomers

  • If that’s not enough, how about this one:

Different Structure

Same Formula

Formula?

Formula?

C4H10

C4H10


Overall problems

Overall Problems

  • Memorizing too many prefixes for large numbers

  • Different chemicals having the same formulas

  • Keep in mind that thus far we’ve only dealt with TWO different elements!


So what to do

H

H

H

C

H

H

C

H

H

H

H

H

H

H

H

H

H

H

H

C

C

C

C

C

H

H

C

C

C

H

H

C

C

C

C

H

H

H

H

H

H

H

H

H

H

H

H

C

H

H

H

So what to do?

  • Number of hydrogens is going to be the same, regardless of isomerism

C5H12

C5H12

C5H12


Solution

Solution

  • Since number of hydrogens don’t change with isomerism, why bother naming them?

  • Name the molecule simply based on number of CARBONS

  • We can always add prefixes or suffixes later for differentiation


Name based on number of carbons

1

2

3

4

5

6

7

8

9

10

Methane

Ethane

Propane

Butane

Pentane

Hexane

Heptane

Octane

Nonane

Decane

Name based on number of Carbons


Did that really help

H

H

C

H

H

H

H

H

C

C

H

H

H

H

H

H

H

H

H

H

H

H

C

C

C

C

C

C

C

C

H

H

H

H

H

H

H

H

H

Did that Really Help?

CH4

Carbon tetrahydride becomes:

Methane

C2H6

Dicarbon hexahydride becomes:

Ethane

C8H18

Octacarbon ???hydride becomes:

Octane


Branches

H

H

H

H

H

H

C

H

H

C

C

C

C

H

H

H

H

H

H

H

H

C

C

C

H

H

H

H

Branches

  • Straight-chain alkanes (Just C & H with single bonds) are now easy

C4H10Butane

  • But how do we deal with branches?

C4H10????


Rules pt 2

Rules pt. 2

  • Identify the longest unbranched chain of carbons

  • Name it as normal

  • Identify the branch

  • Name it but give it a “–yl” suffix

  • Put the names of all branches first, then put name of longest chain


Example

H

Branch is one long

H

C

H

H

H

H

C

C

C

H

H

H

H

Example

methyl

Longest unbranched chain of carbons is three long

propane

Methyl Propane


Practice

H

H

H

H

H

C

C

C

C

H

H

H

H

H

C

H

H

H

H

H

H

H

H

C

C

C

C

C

H

H

H

H

H

H

C

H

H

C

H

H

Practice

Methylbutane

Ethylpentane


One more practice

C

C

C

C

C

C

C

C

It doesn’t matter which way you go!

(Provided you correctly pick the longest unbranched chain)

C

C

One More Practice

MethylButane


Be careful

Methyl

H

H

H

H

H

C

C

C

C

C

H

H

H

H

H

H

C

H

H

This is your longest uninterrupted chain

C

H

H

H

Be Careful

Hexane

Methyl Hexane


A small wrinkle

H

H

H

H

H

C

C

C

C

C

H

H

H

H

H

H

C

H

H

H

H

H

H

H

H

C

C

C

C

C

H

H

H

H

H

H

C

H

H

H

A Small Wrinkle

MethylPentane

MethylPentane

These are different molecules, though!!!


So now what

So Now What?

  • Since two different molecules can’t have the same name, we must differentiate

  • If we look closely, though, the only difference between them is the position of the methyl group


Positioning

H

H

H

H

H

C

C

C

C

C

H

H

H

H

H

H

C

H

H

H

H

H

H

H

H

Here the methyl group is on the second carbon from the end

Here the methyl group is on the third carbon from the end

C

C

C

C

C

H

H

H

H

H

H

C

H

H

H

Positioning

2-

3-

MethylPentane

MethylPentane

So…


Rules pt 3

Rules pt. 3

  • Identify the longest unbranched chain of carbons

  • Name it as normal

  • Identify the branch

  • Name it but give it a “–yl” suffix

  • Put the names of all branches first, then put name of longest chain

  • Put the number of the carbon the branch is on (start numbering from the closest single end)


Practice1

H

H

H

H

H

H

H

C

C

C

C

C

C

C

H

H

H

H

H

H

H

H

C

H

H

H

H

H

H

H

H

H

H

H

C

C

C

C

C

C

C

C

H

H

H

H

H

H

H

H

H

C

H

H

H

H

H

H

H

H

H

C

C

C

C

C

C

H

H

H

H

H

H

H

C

H

H

H

Practice

2-methyl heptane

4-methyl octane

2-methyl hexane


Multiple branches

Multiple Branches

  • So far we’ve only had one branch

  • What happens when there are multple branches?

  • Just add a prefix to indicate the number of a particular type of branch


Practice2

H

C

H

H

H

H

H

H

H

H

C

C

C

C

C

C

C

H

H

H

H

H

H

H

H

C

H

H

H

Practice

2-

methyl

heptane

2-

methyl

2-methyl, 2-methyl heptane

Sounds redundant

2,2 dimethyl heptane


More practice

H

C

H

H

H

H

H

H

H

H

H

C

C

C

C

C

C

C

C

H

H

H

H

H

H

H

H

H

C

H

H

H

H

C

H

H

C

H

H

H

H

H

H

C

C

C

C

C

H

H

H

H

H

C

H

C

H

H

H

H

H

More Practice

2, 6-dimethyl octane

3 ethyl-2,4-dimethyl pentane


Is your arm sore yet

Is your arm sore yet?

  • Are you sick to death of writing all those carbons?

  • Even worse, are you sick of writing all those Hydrogens?

  • How about this…


Shorthand notation

H

H

H

H

H

C

C

C

C

H

H

H

H

H

Shorthand notation

Keep in mind that we have been ignoring the hydrogens for a long time.

Our names have been based entirely on the positioning of the carbons.

So lets now ignore the hydrogens completely!


Is it that easy

H

C

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

C

C

C

C

C

C

C

H

H

C

C

C

C

C

C

C

C

H

H

H

H

H

H

H

H

H

H

H

H

H

H

H

C

H

H

C

H

H

H

H

Is it that easy?


One more

H

Shorthand notation?

C

H

H

C

H

H

H

H

H

H

H

C

C

C

C

C

C

H

H

H

H

H

H

C

H

C

H

H

H

H

H

Name?

One More

3-ethyl-2,4 dimethyl hexane


So is that it

So is that it?

  • Not even close!!

  • There are literally millions of different organic compounds.

  • What else can we do to make things more complicated?


Rings

Rings

  • Thus far we have dealt with chains that are straight or branched.

  • If hydrocarbons are long enough, one end can wrap around and link up with itself!

  • We call these cyclic hydrocarbons.


Cyclic hydrocarbons

Cyclic Hydrocarbons

  • Name the molecule as normal

  • Add the prefix cyclo- to the front of the name of the longest chain

  • Start numbering from the most “important” branch in the ring


Examples

Examples

Cyclohexane

Cyclooctane


More examples

More Examples

Methyl cyclopentane

1,2 dimethyl cyclohexane


Try these

Try These

1 ethyl, 3 methyl cyclobutane

3 methyl, 1 propyl cylclohexane


Multiple bonds

Multiple Bonds

  • So far, even with the cyclic structures we have dealt only with single bonds

  • Carbon can make multiple bonds to another carbon

  • This changes the name

  • Why?


Examine structures

H

H

H

C

C

H

H

H

H

H

H

C

C

H

Examine Structures

C2H6

Ethane- notice that each carbon has four bonds

What will happen to the structure if we double bond the two carbons?

C2H4

Each carbon still has four bonds BUT now the hydrogens have changed!!


Naming molecules with multiple bonds

Naming molecules with multiple bonds

  • Name the molecule as normal

  • Change the suffix of the longest chain name

  • Double bonds = ene

  • Triple bonds = yne

  • Use numbering and prefixes for positioning and multiple multiple bonds.


Organic naming rules

H

H

H

C

C

H

H

C

C

H

H

H

H

H

H

C

C

H

So….

C2H6

C2H2

C2H4

ethane

ethyne

ethene


Practice3

H

C

H

H

H

H

H

H

H

H

H

H

C

C

C

C

C

C

C

H

H

H

H

H

C

C

C

C

C

H

H

H

H

H

H

H

H

H

H

H

H

H

H

C

C

C

C

H

H

H

H

Practice

2-heptene

1-butene

3 methyl-1-pentene


How about in shorthand

Notice the two lines means the double bond is there!

How about in Shorthand?

2 pentene


Practice4

Practice!

Methyl propene

2,4-dimethyl-2-pentene

3-ethyl-2,4,4-trimethyl-1-pentene


Tough ones

Tough Ones

2 methyl 1,3 butadiene

1,2dimethyl-1,4 cyclohexadiene


Triples

Triples?

3, 3-dimethyl-1-butyne

1,4 cyclohexadiyne


So that s it right

So that’s it, right?

  • Not even close, bud.

  • All this….all this was just for two elements, carbon and hydrogen!!

  • We haven’t even dealt with any of the others, yet.


Wait don t jump

Wait!! Don’t jump!!

  • Get off that bridge.

  • It’s not that bad provided we arrange things in an organized fashion!


Functional groups

Functional Groups

  • Nature has done us a favor.

  • There are many common groups that we can organized or file into different categories.

  • Then we can name them based on these categories.


Functional groups1

Functional Groups

  • A group of atoms that, when added to a hydrocarbon chain, alter the chemical properties of the chain.

  • Just a few different functional groups to know…


Functional groups2

Halogens

Alcohols

Ethers

Aldehydes

Ketones

Carboxylic Acids

Esters

Amines

R-F, R-Cl, R-Br, R-I

R-OH

R-O-R

R-COH

R-CO-R

R-COOH

R-COO-R

R-NH2

Functional Groups


Halides

Halides

  • Fluorides, Chlorides, Bromides, and Iodides

  • Simply name the molecule as normal but add the prefix Fluoro, Chloro, Bromo, or Iodo as necessary


Halides1

Cl

Cl

I

I

Halides

2, 3 dichlorohexane

3, 3 diiodo-1-pentene


Alcohols

Alcohols

  • R-OH

  • Name like normal except add an –ol suffix


Alcohols1

OH

OH

H

H

OH

H

C

C

H

H

Alcohols

2 propanol

1cyclobutenol

ethanol


Ethers

Ethers

  • R-O-R

  • Name two “R” groups with –yl endings

  • End name in ether


Ethers1

O

O

Ethers

Dimethyl ether

Ethyl methyl ether


Aldehyde

Aldehyde

  • R-COH

  • This is a carbon to oxygen double bond with a hydrogen at the end.

  • Name as normal except use a “-al” suffix


Aldehydes

O

H

H

H

H

C

C

C

C

H

H

H

H

O

H

H

Cl

H

H

C

C

C

C

C

H

H

H

Cl

H

Aldehydes

butanal

3,3 dichloropentanal


Ketones

Ketones

  • R-CO-R

  • This is a carbon to oxygen double bond but in the center of a hydrocarbon chain rather than the end

  • Name as normal but give it a “-one” suffix


Ketones1

O

H

H

H

C

C

C

H

H

H

O

H

H

H

H

H

H

C

C

C

C

C

C

H

H

H

H

H

H

Ketones

propanone

2 hexanone


Carboxylic acids

Carboxylic Acids

  • R-COOH or R-CO2H

  • This is a carbon to oxygn double bond with the same carbon single-bonded to an OH group.

  • Name as normal except give it the suffix “-anoic acid”.

HC2H3O2


Carboxylic acids1

O

H

H

H

H

C

C

C

C

OH

H

H

H

O

H

H

HO

C

C

C

F

H

H

Carboxylic Acids

Butanoic acid

3-Fluoropropanoic acid


Esters

Esters

  • R-COO-R

  • This is a carbon to oxygen double bond with a carbon to oxygen single bonded to another single bonded carbon

  • Name by given secondary branch “-yl” suffix and main branch “-anoate” suffix.


Esters1

Secondary Branch

Main Branch

O

H

H

H

H

H

H

C

C

C

C

C

O

C

H

H

H

H

H

H

Esters

methyl

pentanoate

Methyl Pentanoate


Esters2

O

H

H

H

H

H

H

H

C

C

C

O

C

C

C

C

H

H

H

H

H

H

H

O

H

H

H

H

H

H

H

C

O

C

C

C

C

C

C

H

H

H

H

H

H

H

Esters

Butylpropanoate

Methyl hexanoate


Amines

Amines

  • R-NH2

  • Name the “R” group or groups with “-yl” endings

  • Add the word “amine”


Amines1

H

H

H

C

N

H

H

H

H

H

C

N

H

C

H

H

H

Amines

Methylamine

Dimethylamine


Summary

O

O

R

H

R

R

C

C

Cl

OH

R

R

Alcohol

Ether

Halide

R

R

O

Ketone

Aldehyde

O

OH

R

C

Carboxylic Acid

O

O

R

R

C

NH2

R

Ester

Amine

Summary


Summary1

Alkanes

Alkenes

Alkynes

Halides

Alcohols

Ethers

Aldehydes

Ketones

Carboxylic Acids

Esters

Amines

-“-ane”

=“-ene”

“-yne”

R-X“-o”

R-OH“-ol”

R-O-R“-yl ether”

R-COH“-al”

R-CO-R“-one”

R-COOH“-anoic acid”

R-COO-R“-yl” “-anoate”

R-NH2“-yl amine”

Summary


Can you do this

Can You Do This?

  • YES!

  • It takes:

  • Memorization

  • Practice

  • Practice

  • Practice

  • Practice

  • And, oh yes…

  • Practice!


  • Login