A chemist writes the condensed formula CH₃CH(OH)CH₂C(CH₃)₃…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A chemist writes the condensed formula . Find the carbons in the longest chain that holds the OH carbon. Find the number given to the OH carbon when the chain is numbered correctly. Find how many methyl branches the chain carries. Then give the full name and the class.
Need a reminder? The key ideaShow
An alcohol has OH on a saturated carbon. Class: count the carbon neighbours of the OH carbon (1 primary, 2 secondary, 3 tertiary). Name: longest chain with the OH carbon, lowest number to OH, ending -ol. Mass percentage of an element: .
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Given. .
Step 1. The chain. Start at the CH on the left, then CH(OH), then CH, then the quaternary carbon, then one of its methyl groups. That is 5 carbons.
Step 2. Numbering. Counting from the left end gives the OH carbon the number 2. From the right end it would be 4. Choose 2.
Step 3. Branches. The quaternary carbon is number 4 and holds two more methyl groups. That is 2 methyl branches, both on carbon 4.
Step 4. Name and class. The name is 4,4-dimethylpentan-2-ol. The OH carbon has two carbon neighbours, so the alcohol is secondary.
Check. Pentane has 5 carbons, and 5 + 2 = 7 carbons in all. Count the formula: CH, CH, CH, C and three CH make 7 carbons. They agree.
Discussion (0)
Log in to join the discussion.
Loading…