H-ZSM-5-CATALYZED SHAPE-SELECTIVE ACETALIZATION OF ALDEHYDES

The paper describes acetalisation of aliphatic and aromatic aldehydes with methanol catalysed by H-ZSM-5 at room temperature. The reactions are characterised by the following features: 1. (1) The reaction rates are faster with aromatic aldehydes relative to the aliphatic aldehydes. 2. (2) The reaction exhibits shape selectivity for aliphatic aldehydes. The phenomenon of shape selectivity with the aliphatic aldehydes studied has been corroborated by carrying out kinetics of adsorption of the aldehydes and the product acetals. The activity and selectivity pattern of H-ZSM-5 has been compared with other acid catalysts. The utility of the shape selective acetalisation of H-ZSM-5 in selectively reducing one aldehyde in presence of the other with sodium borohydride is also pointed out. © 1991.