What does the bracket around the ethyl group mean ? and how do you name this using the IUPAC system?

Question

(CH3Ch2)2CHCHOHCCH3CH3CH3 ? (there are 2 methyl groups on the 2nd Carbon and an alcohol on the 3rd carbon)

Answer 1

The (CH₃CH₂)₂ at the end means there are 2 ethyl groups attached to the next carbon atom. It's not exactly the way it should be written if you're using inline notation. I would rewrite it as:

 

CH₃CH₂CH(CH₃CH₂)CHOHC(CH₃)₂CH₃

 

That makes the longest chain containing the -OH (which is the parent group of the compound) as 7 carbons. But the OH on C-3, two methyls on C-2, and the ethyl on C-5.

 

Jim S.