Back to Chemistry 1405 Concept Reviews

Name of Functional Group	Alcohol	Thiol	Phenol	Ether
Special Characteristic	-OH is attached to a carbon	-SH is attached to a carbon	-OH is attached to a benzene ring	An oxygen is bonded to two carbons
Example

Naming Alcohols:

Step 1: Find the longest continuous chain of carbon atoms that contains the –OH group, and use the name for a chain with that number of carbons but change the ending to “-ol”.

Example: 1406 Ch 12 img 5.png
The longest carbon chain is 4, so I know I have “butanol”

Step 2: Number the carbon atoms in the longest chain, beginning with the end nearest to the alcohol (-OH) group, and give the number of the carbon with the –OH group in the name of the compound.

Example: 1406 Ch 12 img 6.png

The –OH is on carbon 2, so I know I have “2-butanol”

Step 3: Name each substituent and assign a number indicating its location on the main chain. Follow the same rule for naming substituents that you have used in the past (i.e.-use prefixes like di- and tri- for multiple substituents of the same name and list the substituents in alphabetical order)

Example: 1406 Ch 12 img 7.png

There are two methyl groups both of which are on carbon #3, so I would give a number to each one of them and call this “3,3-dimethyl-2-butanol”

Naming Phenols:

All phenols are simply called “phenol.” There is no number indicating where the –OH group is since, in any cyclic alcohol, the –OH is automatically considered to be attached to carbon #1. Substituents on phenols are named as always.

Naming Thiols:

The naming method for Thiols is EXACTLY the same as alcohols EXCEPT that the ending is “-thiol” instead of “-ol” and the “e” of the carbon chain name is not dropped. For example, if the compound shown in the example on the previous page had an –SH instead of an –OH, it would be named 3,3-dimethyl-2-butanethiol.

Naming Ethers:

*Naming Method*	*Common Naming*	*IUPAC Naming*
Step 1	Identify the groups on either side of the oxygen, and name them like substituents.	Look for the longest carbon chain that is attached to the –O-, and number the carbons starting on the side closest to the oxygen. Example:
Step 2	Name the two groups in alphabetical order followed by the word “ether”. There should be a space between each group and the word “ether”. Example: Ethyl methyl ether	Identify and name the smaller group containing the oxygen. For the name, start with the name of a hydrocarbon with that many carbons and change the ending to “-oxy”. This group will be treated like a substituent. Example:
Step 3	N/A	Name the “-oxy” group and the substituents in alphabetical order, assigning numbers to their locations based on the carbon from the longest chain to which they are bonded. Example: The name is then *2-ethoxy-2-methylpropane*.