Convenient preparation of 1,1-diacetates from aromatic aldehydes catalysed by zinc-montmorillonite

1,1-Diacetates were produced from a variety of aromatic aldehydes using Zn-montmorillonite as a catalyst. The procedure generally resulted in good yields (98%) of aromatic aldehydes including those carrying electron donating- or withdrawing substituents. The great advantage of the application of Zn-montmorillonite catalyst is that the reaction takes place under mild conditions. In addition, the zinc cation exchanged form of montmorillonite has a minimal environmental impact.