Dependence of endo and exo selectivities on the water contents available in salt solutions for the reaction of cyclopentadiene with methyl acrylate

The effect of the water contents present in different salt solutions on the endo selectivities has been investigated for the Diels-Alder reaction of c yclopentadiene with methyl acrylate. For aqueous LiCl and CaCl2, endo produ ct increases with an increase in the moles of water and then remains almost invariant at higher water content. On the contrary, a regular decrease in endo product is noted in aqueous guanidinium chloride and LiClO4 solution r eaching a tapering at higher water content. The results show that the avail able surface area can provide an effective method to alter the endo/exo rat ios of a Diels-Alder reaction. Copyright (C) 2000 John Wiley & Sons, Ltd.