Synthesis of acyclic analogs of N‐acetylmuramyl‐L‐alanyl‐D‐isoglutamine (MDP)

The syntheses of the acyclic MDP analogs 27 – 37 is described, the carbohydrate moiety of muramic acid being replaced by acyclic amino alcohol structures. Their preparation was accomplished by hydrolytic cleavage of the cyclic, disubstituted 3‐morpholinones 2 – 5 and protection of the free amino group to give the compounds 6 – 9 . Coupling with the dipeptide L ‐alanyl‐ D ‐isoglutamine benzyl ester, cleavage of the N ‐protecting group, acylation with acyl chains of various lengths and hydrogenation produced the title compounds 27 – 37 . The latter exhibit variable lipophilic character.