Download Organic Structures

Organic Structures
There are an endless variety of organic structures that you could have found. Some possible functional groups contained within
these structures are given below, grouped according to their functional group level.
Level 1 Functional Groups. Each Level 1 carbon atom (in red) has one bond to a heteroatom (shown in blue).
In each structure, the group 'R' could be the carbon atom from an alkyl group or aryl group, or it could be a hydrogen.
Level 2 Functional Groups. Each Level 2 carbon atom (in red) has two bonds to heteroatoms (shown in blue).
Level 3 Functional Groups. Each Level 3 carbon atom (in red) has three bonds to heteroatoms (shown in blue).
Level 4 Functional Groups. Each Level 4 carbon atom (in red) has four bonds to heteroatoms (shown in blue).
The functional groups for the molecules in the activity are given below. The functional group levels of the carbon atoms marked
with a red dot are given.
Going further
In general, oxidations go up the levels and reductions go down. So, for example, oxidising a primary alcohol to a carboxylic acid is a change
from a Level 1 functional group to a Level 3 functional group. Reducing a ketone to a secondary alcohol is a change from a level 2 functional
group to a level 1 functional group.
In contrast, substituting one heteroatom for another will not change the functional group level. Substitution only changes the functional group
level when a heteroatom is replaced by a carbon atom, for example when an alkyl halide reacts with cyanide. As the heteroatom is removed,
the function group level of the original carbon falls by one, possibly to zero. The newly-introduced carbon is Level 3, as it has three bonds to a
nitrogen atom, for example:
Hydrolysis also does not change the functional group level. Although a bond to a heteroatom is broken, it is replaced by a bond between the
carbon and oxygen, for example:
When faced with an unfamiliar reaction, working out the functional group level of the reacting carbon may help you decide what type of
reaction has taken place and to suggest reagents and/or conditions.