Naming Thiols - Online Tutor, Practice Problems & Exam Prep

Rules for Naming Thiols Concept 1

Here we're going to say that thiols, also called mercaptans, possess a mercapto group. "Mercapto" just means SH group, connected to a carbon atom. Now the set of rules for naming thiols is very similar to the ones used to name alcohols. Here, all we do is add "thiol" to the parent chain name. So our naming convention will be the location of our different substituents, then we have the location and then the parent, and then our final name. Right? This is the way we would approach naming different types of files.

Naming Thiols Example 1

Name the following thiol compound. Right. So step 1 says to find the longest carbon chain because it'll represent the parent chain, and assign a name according to the prefixes. Now, the parent chain should include the SH group, the mercapto group, and have the largest number of carbons. If there is a tie between the longest chain, choose the chain with more substituents. If we take a look here, our longest chain would have to be this chain. Now we have our longest chain, so we have to, let's see, assign names according to the prefix. We're going to assign names to all the substituents here. So we know that this SH group is going to become a thiol. It's going to form near the end of the name, so we won't worry about it yet. We have "br" here, which is bromo, and one carbon here is methyl.

Step 3 is we start numbering the chain from the end closest to the SH group. So the end close to the SH group is here: 1, 2, 3, 4, 5, 6. If there's a tie, number from the end closest to the next substituent. If it's still a tie, number in alphabetical order. Assign the numerical location to the carbon with the SH group, which we did. And then steps 4 to 6 will repeat steps from previous naming topics. So here this is what it would look like. Alright, so we'd say we have bromo and methyl. We name those alphabetically. So bromo is on 3, so 3-bromo. 5-methyl. Then we're going to say that the thiol group, the mercapto group, is on carbon 2, so 2. It's a 6-carbon chain, so hexanethiol. Okay? So this would be the name of this particular thiol compound.

Determine IUPAC name for given compound.

• A. 1,2-hexenedithiol
• B. 5,6-hexanedithiol
• C. 5,6-heptanedithiol
• D. 1,2-hexanedithiol

Determine IUPAC name for given compound.

• A. 3-heptene-3-isopropyl-2-thiol
• B. 3-isobutyl-4-heptene-2-thiol
• C. 3-isopropyl-3-heptene-2-thiol
• D. 4-heptene-3-isobutyl-2-thiol

Draw skeletal structural formula for 2-ethylcyclopentanethiol.

• A.
• B.
• C.
• D.