Efficient syntheses of bolaform surfactants from l-rhamnose and/or 3-(4-hydroxyphenyl)propionic acid†
Abstract
The efficient syntheses of new symmetric and asymmetric bolaamphiphiles derived from L-rhamnose and/or 3-(4-hydroxyphenyl)propionic acid are described. The bolaamphiphiles are obtained with good to high yields through a two-step reaction sequence involving, successively, a glycosylation (or an esterification) and a metathesis. The glycosylation was performed without solvent because the alcohols could be the solvent in this reaction. For the esterification, enzymatic catalysis was used which gave esters with high yields which increased with the carbon chain length. Finally, the metathesis step was performed in the presence of a Grubbs’ I catalyst without protection steps in only dichloromethane without the addition of methanol.