A synthesis of 1-O-octadec-cis-1′-enyl-L-glycerol

Abstract

An exchange reaction between octadecanal dimethyl acetal and D-(glycerol 1,2-carbonate) gave octadecanal di-D-(glycerol 1,2-carbonate) acetal which was converted into 3-O-(1-chlorooctadecyl)-D-glycerol 1,2-carbonate by the action of acetyl chloride at room temperature. The chloro-ether was treated with triethylamine to give a mixture of the cis- and trans-isomers of 3-O-octadec-1′-enyl-D-glycerol 1,2-carbonate in which the cis isomer predominated. Alkaline hydrolysis of the carbonates gave a mixture of the cis- and trans-isomers of 1-O-octadec-1′-enyl-L-glycerol which was acylated with acetic anhydride or hexadecanoyl chloride in pyridine to give the diacetates or dipalmitates. The cis- and trans-isomers of the diacetates and dipalmitates were separated by t.l.c. on silica gel–silver nitrate plates. Alkaline hydrolysis of the cis-isomer of the diacetate gave the title compound.