Long-range stereo-relay: relative and absolute configuration of 1,n-glycols from circular dichroism of liposomal porphyrin esters

The relative and absolute configurations of long-chain syn- and anti-1,5-, 1,7- and 1,9-glycols were determined from exciton-coupled circular dichroism (ECCD) of the corresponding bis-5-(4'-carboxyl)-5,10,15,20-tetraphenylporphyrin esters measured in uniform (phi = 26 nm), unilamellar liposomes. Long-range transmission of configuration by ECCD is made possible through partial ordering of glycol ester-lipid molecules by liposomal bilayers.