Synthesis of Glycerophosphonolipids Containing Aminoalkylphosphonic Acids
1,2-Di-O-octadecyl- and 1,2-di-O-hexadecanoyl-sn-glycerol 3-(2-aminoethyl)phosphonate (21) and (22) and the (3-aminopropyl)phosphonate analogues (23) and (24) were prepared with the aim of obtaining enzyme (lipase)-stable liposomes.New reactions were devised and classic methodologies were modified in order to transform D-mannitol (6) into optically pure 1,2-di-O-substituted sn-glycerols (12) and (13) (R=C18H37 and C15H31CO).Benzyloxycarbonylaminoalkylphosphonic acids (5a) and (5b) were then coupled with the glycerols by means of condensing reagents such as 2,4,6-triisopropylbenzenesulphonyl chloride.The resulting N-protected lipids were catalitically hydrogenated to furnish compounds (21)-(24) in overall yields of 10-20 percent from compound (6).