Mechanism of Acid-Catalyzed Acetal Formation

Acetal derivatives of aldehydes and ketones are prepared by an acid-catalyzed dehydration reaction with alcohols or diols. An example is shown below.
Writing a mechanism for this reaction provides a good test of ones' understanding of acid-catalyzed processes.

a) The first step in this process must be an acid-base proton transfer.
Click on the basic atom that is protonated to initiate this transformation.

When you have made a correct selection, an equation showing the reaction for that step will appear, and a new question will be posed. Incorrect selections will open an alert window displaying an explanatory message. The overall transformation will remain displayed in the colored box at each stage.

The Mechanism of Acetal Formation

Choose a nucleophile from the reactants in the colored box.

The Mechanism of Acetal Formation

Hint: Choose a base from the reactants in the colored box.

Acetal Formation

Congratulations. You have finished this problem. A summary of the steps in this acid-catalyzed mechanism is shown below.

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