Phospholipids Chiral at Phosphorus. 5. Synthesis and Configurational Analysis of Chiral Phosphatidylethanolamine

Article abstract of DOI:10.1021/ja00315a049

We report the synthesis and configurational analysis of 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) chirally labeled with 17O and 18O at the phosphate head group.Condensation of (S)-1,2-dipalmitoyl-sn-glycerol, P17OCl3, and N-(1-phenylethyl)-2-aminoethanol gives a diastereomeric mixture of cyclic oxazaphospholidines.The two diastereomers were separated by coloumn chromatography.Ring opening with H₂18O followed by hydrogenolysis with H2/Pd gives (R_p)- and (S_p)-<17O,18O>DPPE.The relative configuration and isotopic enrichments of <17O,18O>DPPE can be analyzed by 31P NMR following silylation of DPPE.To determine the absolute configuration, the two diastereomers of <17O,18O>DPPE are converted, by a combined organic and biochemical procedure, into (R_p)- and (S_p)-1-<16O,17O,18O>phospho-(R)-propane-1,2-diol, with all P-O bonds intact.The configuration of the latter compound is then analyzed by 31P NMR as reported previously (Buchwald, S.L.; Knowles, J.R.J.Am.Chem.Soc. 1980, 102, 6601-6603).