How to Name Cyclic Aldehydes: A Step-by-Step Guide with Examples

Naming cyclic Aldehydes

Acetaldehyde

The naming of cyclic aldehydes follows the same rules as naming regular aldehydes. The suffix “al” is added to the name of the corresponding parent hydrocarbon to indicate the presence of an aldehyde group (-CHO). However, the prefix for the cyclic hydrocarbon must also be included.

The steps to name a cyclic aldehyde are as follows:

1. Count the number of carbons in the ring and write the correct prefix (e.g. cyclo-, bicyclo- for a ring with two bridges, tricyclo- for a ring with three bridges, etc.).

2. Identify the aldehyde group (-CHO) attached to one of the carbons in the ring.

3. Name the parent hydrocarbon without the “-e” ending and add the suffix “-al” to indicate the presence of the aldehyde group.

4. Number the carbons in the ring starting from the carbon where the aldehyde group is attached. The aldehyde carbon is always assigned the number 1.

5. Write the name as a single word, with the prefix, the number of carbons in the ring, the parent hydrocarbon name, and the suffix “-al”. For example, cyclohexanecarbaldehyde, or 2,5-dimethylcycloheptanecarbaldehyde.

It is important to note that the numbering of the carbons in the ring starts from the carbon where the aldehyde group is attached, regardless of whether there are other functional groups present in the ring. Also, the aldehyde group is always given the number 1 when numbering the ring.

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