Which of the following structures represents an $\mathrm{ether}$?

• A. $\mathrm{CH}{3}_3-\mathrm{OH}$
• B. $\mathrm{CH}{3}_3-\mathrm{NH}{2}_2$
• C. $\mathrm{CH}{3}_3-\mathrm{COOH}$
• D. $\mathrm{CH}{3}_3-O-\mathrm{CH}{3}_3$

Answer: (D)

Verified step by step guidance

1. Recall the definition of an ether: an ether is an organic compound where an oxygen atom is connected to two alkyl or aryl groups, represented as R-O-R'.
2. Examine each given structure to identify the functional groups present. For example, CH3-OH is an alcohol, CH3-NH2 is an amine, and CH3-COOH is a carboxylic acid.
3. Look for the structure where an oxygen atom is bonded to two carbon-containing groups without any hydrogen attached to the oxygen, which is characteristic of ethers.
4. Identify the structure CH3-O-CH3, where the oxygen is bonded to two methyl groups, fitting the ether functional group criteria.
5. Confirm that this structure does not contain other functional groups like -OH, -NH2, or -COOH, which would indicate alcohols, amines, or carboxylic acids instead.