The synthesis of chiral glycerides starting from D- and L-serine.
A method for synthesizing chiral glycerides starting from L- or D-serine is described. Optically-active serine (both enantiomers are commerically available) was transformed into glyceric acid by stereospecific diazotization. The configuration at carbon atom 2 was maintained during the reaction. The glyceric acid was then converted into optically pure isopropylideneglycerol - which is an important intermediate in the synthesis of mono-, di- and triglyderides - by esterification followed by acetalization with acetone and reduction with lithium aluminium hydride. Reaction of this intermediate with triphenylphosphine in tetrachloromethane followed by acid-catalysed hydrolysis and dehydrohalogenation provided optically-active glycidol (2,3-epoxy-1-propanol). The epoxy ring of an ester of glycidol and a fatty acid was then opened stereospecifically with retention of configuration by heating the glycidol ester in the presence of a second fatty acid and a catalyst. This yielded a chiral 1,3-diglyceride which could be converted into a chiral triglyceride.
D004075:Diglycerides / Q000138:chemical synthesis; D005989:Glycerides / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D008722:Methods; D008968:Molecular Conformation; D009904:Optical Rotation; D012694:Serine; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D014280:Triglycerides / Q000138:chemical synthesis
D004075:Diglycerides; D005989:Glycerides; D014280:Triglycerides; D012694:Serine