Novel Regiocontrolled Protection of 1,2- and 1,3-Diols via Mild Cleavage of Methylene Acetals

The regiocontrolled protection of unsymmetrical 1,2- and 1,3-diols has been developed. Different types of protected diols are available from the methylene acetal In a one-pot procedure. Highly regioselective protection of diols with a silyl group at the less hindered hydroxy group as well as with a MOM group at the more hindered one were achieved. The reaction conditions are mild without affecting other functional groups including acid-labile function.