How+to+name+Ketones

Introduction to Ketones

The carbonyl group found in Ketones is the group in red In ketones, the carbonyl carbon has two organic groups, which we can represent by R1 and R2 so the formula of a ketone is:

The R groups may be alkyl or aryl.
 * How to name Ketones **//

Ketones are named using the suffix -one. the carbon of the functional group is counted as part of the root of the chain so the simplest Ketone: is called propanone. No ketone with fewer atoms is possible. The naming of ketones is actually fairly simple. It is very similar to the naming of alcohols. Example
 * 1) You start by choosing the longest carbon chain you can find that includes the carbon from the carbonyl group and use the length of that carbon chain as your base name.
 * 2) You change the ending by removing the **-ol** and adding **-one**, and adding a number between the now shortend stem and the sufix to indicate which carbon is double bonded to the oxygen.
 * 3) Then, if there are any side groups attached to the main chain, those are added to the front of the name with the appropriate numbers to show their location.

We do not need to number the carbon in propanone because the funtcional group can only be in one place this is the same for butanone:

H H H H-C-C-C-C-H H O H H

Butanone is formed from 2-butanol. The carbon chain is four carbon atoms long. Therefore, we have "butane" as a starting point. One of those carbons is double bonded to an oxygen. This makes the compound a ketone. This means that we replace the -e ending on the "butane" with an -one ending to get butanone. (We could also use a 2- in front of this name to indicate that it is the 2nd carbon which is a member of the carbonyl group. This gives the name 2-butanone for this particular compound. However, the 2- is unnecessary here since if the carbonyl group were to be moved one carbon to the right we would start numbering from the right side of the compound and that carbon would be #2.) the alcohol we start off with and the ketone we end up with has the same number of carbon atoms also the carbonyl group in the ketone is in the same postion of the -ol group in the alcohol which is important when trying to make a parcticular ketone.

H-C--C--C--C-H H OH H H 2-butanol || K2Cr2O7 ¾¾¾¾¾¾® H2SO4, heat ||  H H H H-C-C-C-C-H
 *  H H H H
 * || | |H O H H butanone ||  + 2[H] ||

Example 2

H H H H H-C-C-C-C-C-H H H O H H

 so
 * 1)  there are 5 carbons in the longest chain therefore the stem will be pent-
 * 2)  change what would be the -ol to -one so pentanol would become pentanone and the functional group in on the third carbon so the number 3 is added to the beginning: 3-pentanone

<span style="color: #ff0000; display: block; font-family: 'Arial Black',Gadget,sans-serif;">Example 3

<span style="color: #ff0000; display: block; font-family: 'Arial Black',Gadget,sans-serif;"> H <span style="color: #ff0000; font-family: 'Arial Black',Gadget,sans-serif;">| H-C-H H | O H H-C--C--C--C-H H H so
 * 1) there are 4 carbons on the longest chain so the stem will be but-
 * 2) change what would be -ol to -one to butanone and the functional group is on the 2nd carbon so 2-butanone
 * 3) there is a methyl group on the 3rd carbon so 3-methyl 2- butanone

Now see if you can name this:

H CH3 CH3 H H H H-C--C--C---C--C--C--C-H H O H H H H H If there is a carboxyllic acd on the end of a ketone a prefix is needed -oxo and a number is needed to show which carbon the double bonded oxygen is on : 0 O || || CH3 - C - C | OH 2-oxo-propanoic acid