Iron(III) Chloride as a Water-Compatible Lewis Acid for Diastereoselective Aldol Reactions in Water in the Presence of a Surfactant

Diastereoselective aldol reactions of various aldehydes with silicon enolates in water have been successfully carried out using iron(III) chloride and a surfactant. Contrary to previous understanding, iron(III) chloride has been shown to be a watercompatible Lewis acid. In this catalytic system, epimerization of the product was not observed, and this result indicates that the diastereoselectivity was controlled kinetically.