Ferric Hydrogensulfate as Effective and Recyclable Catalyst for Mild Dithioacetalization of Aldehydes and Ketones

Ferric hydrogensulfate has been found to be an extremely efficient and recyclable heterogeneous catalyst for dithioacetalization reactions. Carbonyl compounds have been successfully converted into their corresponding dithiolanes and dithianes derivatives in excellent yields at ambient conditions. The synthetic simple procedures reported in this paper constitute an exceptionally mild procedure for selective carbonyl protection.