Ketones

Are you tired of all the functional groups? Try this song, by the band the Keytones.  It might just brighten your day and making studying a little more pleasant!  Their name's not quite the same, but I accidently stumbled on it because I have horrible spelling.

The Keytones- It's Good to be Alive

Keytones have a variety of uses.  They can be uses as welding agents, industrial solvents, and is a type of sugar.

Erythlurose: ketone sugar found in rasberries.

Ketone bodies are three molecules used in our bodies.  They are used as an energy source for our hearts and brain.  As you can see, they are very important!

Keytones are often acidic.As well, often they  form cyclic patterns.

 

There general structure is:

Each 'R' stands for a Carbon chain.  R' means that the Carbon chain may or may not be different from the one on the left.  As you can see, there is once again another Carbonyl group.  The Oxygen is double bonded to the Carbon(the intersection).

What's the difference between Aldehydes and keytones? Aldehydes are only bonded to one Carbon chain whereas ketones are bonded to two.  Remember: R and R'.  An easy way to remember is:

aldeHYDes have HYDrogens and Ketones have Karbon chains.

It's like Ariel and her sisters all over again, but this time it's a different sister. 

Rules for naming ketones.

1) Identify the longest carbon chain.

2) Assign each Carbon a number.  Give the lowest numbers possible.  Instead of 4,4,5 make it 1,2,2. 

3) Count the number of Carbons.  This will be your parent chain so name the chain as if it were an alkane.

4) Take the 'ane' off the end and add the suffix 'one'.

5) The ketone isn't necessarily at the beginning of the chain so you must dicate its location.

6)Name the other substituents and add them to the name at the beginning.  Arrange them in alphabetical order.  

 

Let's do some practise.

Count the number of Carbons.  There are 6, so the chain without the double bonded Oxygen would be hexane.  Then add the suffix 'one' by taking off 'ane'.  But note that the Carbonyl group isn't on the '1' Carbon so you need to give it the lowest possible number(2).  Write the number before the chain name.  Therefore 2-hexanone.

 

Now let's do a slightly trickier one.

Find the longest chain of Carbons with the Carbonyl group.  You see that the chain will be 4 Carbons long and that there will be an extra methyl group.  Add this after naming the main chain.  The double bonded Oxygen sits on the second Carbon so the parent chain is 2-butanone. The methyl group sits on the third Carbon so the name is 3-methyl.  Put the two together and, voila! 3-methyl-2-butanone!