Synthetic methods for the preparation of basic [formula omitted]- and [formula omitted]-pseudo-sugars. Synthesis of carbocyclic analogues of [formula omitted]-acetyl-muramyl- [formula omitted]-alanyl- [formula omitted]-isoglutamine (MDP)

Abstract

Two exocyclic olefins 10 and 22 readily elaborated from D-glucosamine have been transformed by Ferrier rearrangement reaction into amino-cyclohexanones 11 12 and 23 24. Reduction of ketone 11 with tri-t-butoxy-aluminium hydride followed by sequential acetylation and hydrogenolysis gave the acid 14 which was coupled with dipeptide 15 to provide 16. Alkaline hydrolysis of the latter afforded 1 a carbocyclic nor-analogue of MDP. The second target molecule 2 was prepared from an oxazolidine-pseudo- D-glucosamine 27 obtained by treatment of amino-cyclohexanone 23 with methoxymethylenetriphenylphosphorane and mercuric acetate-sodium borohydride reagents as key steps in the synthesis. On the other hand hydroboration of the olefin 31 yielded pseudo- L-idosamine derivative 28. Birch reduction of 27 followed by sequential benzylidenation etherification with (S)-α-chloropropionic acid and condensation of the resulted 36 with dipeptide 15 gave 36. Hydrogenolysis of the latter afforded the carbocyclic analogue 2 of MDP.