Which of the following are not ethers?
A. Anisole
B. Cumene hydroperoxide
C. Ethylene oxide
D. Sodium phenoxide
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → B and D only
An ether has an oxygen atom bonded to two carbon atoms, R–O–R′. The groups may be alkyl or aryl, and the oxygen may also sit in a ring (cyclic ether). A compound is not an ether if its oxygen is bonded to hydrogen, to another oxygen or to a metal ion.
(A) Anisole — An ether. In \( \ce{C6H5-O-CH3} \) the oxygen joins a phenyl and a methyl group (methoxybenzene).
(B) Cumene hydroperoxide — Not an ether. \( \ce{C6H5C(CH3)2-O-O-H} \) has an O–O–H group, so it is a hydroperoxide.
(C) Ethylene oxide — An ether. In oxirane the oxygen joins two \( \ce{CH2} \) groups in a three-membered ring, so it is a cyclic ether (an epoxide).
(D) Sodium phenoxide — Not an ether. In \( \ce{C6H5O^{-}Na^{+}} \) the oxygen is bonded to one carbon only and carries a negative charge; it is the salt of phenol.