Mild Deprotection of Methylene Acetals in Combination with Trimethylsilyl Triflate‐2,2′‐bipyridyl.

The facile deprotection of methylene acetal protection of diols under mild conditions is established. The combination of trimethylsilyl triflate (TMSOTf) and 2,2'-bipyridyl followed by a weakly acidic hydrolysis was effective and the substrates having acid sensitive functional groups can be tolerated under the stated conditions. The selective deprotection between methylene acetal and benzophenone ketal was achieved.