Can someone please help me with this Question?

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1 Answer
Apr 24, 2018

The correct answer is (1).

Explanation:

#"PCl"_5# cleaves alkyl ethers and forms alkyl halides. It does not cleave aromatic ethers.

Thus, the reaction with cyclohexyl phenyl ether gives chlorocyclohexane and phenol.

Overall

The mechanism probably involves an #"S"_text(N)2# attack of the ether #"O"# on the #"P"# atom.

Step 1

Then, in a second #"S"_text(N)2# reaction, the chloride ion attacks the α carbon of the cyclohexyl group to form cyclohexyl chloride.

Step 2

Aqueous workup hydrolyzes the aromatic phosphorus compound to phenol and #"POCl"_3#.