Ion-exchange resin-catalysed ketalization of acetone with 1,4-and 1,2-diols: use of molecular sieve in reactive distillation

Ketalization of acetone with 1,4- and 1,2-diols was carried out in the pres ence of cation exchange resin catalysts to obtain corresponding cyclic keta ls viz. dioxepins, dioxepanes and dioxolanes. The reaction is equilibrium c ontrolled and low conversions were achieved in batch mode. Molecular sieves in semi-batch reactive distillation mode were used to remove the water fro m the reaction mixture. This resulted in high conversion of the limiting di ol. The batch kinetics was explained by a pseudohomogeneous model. The effe cts of different configurations as well as various parameters were studied in detail to arrive at optimum conditions. An engineering solution was arri ved at to make the process industrially feasible. (C) 1999 Elsevier Science B.V. All rights reserved.