Esterification of aldehydes and alcohols with pyridinium hydrobromide perbromide in water

The direct esterification of aldehydes and alcohols was carried out with pyridinium hydrobromide perbromide in water at room temperature. A variety of aldehydes were converted to respective ester derivatives with alcohols such as methanol, 1,2-ethanediol, 1,3-propanediol. Further, a variety of aliphatic alcohols were also converted to the corresponding Tishchenko-like dimeric esters in good yields under the same reaction conditions.