Would an acceptable way to protect a phenolic alcohol be through a Williamson ether synthesis? As in:

1) Deprotonating phenol with sodium hydroxide.

2) Addition of methyl iodide.

3) Deprotection of ether with strong, hot, concentrated acid such as HI.

I know there are more sophisticated ways of protecting alcohols, but what's wrong with this method (if any)? It certainly seems relatively simple and effective.


Protecting a phenol by using the Williamson ether synthesis to make the methyl ether is an acceptable method. However your deprotection step using strong, hot acid is undesirable since the molecule might contain acid or thermally sensitive groups. A milder way to deprotect a phenolic methyl ether involves the use of boron tribromide.

Here's a nice link to a page listing a variety of methods to protect and deprotect phenols, with examples for each route. Depending on your actual molecule, the dimethyl sulfate protection route might be preferred.

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