Synthesis of an acryloyl‐type polymer pending D‐glucose analog of N‐acetylmuramyl‐L‐alanyl‐D‐isoglutamine

Abstract

AbstractPoly{1‐{3‐[O‐1‐(1‐carboxyethylaminocarbonyl)ethyl]‐6‐O‐D‐glucopyranosylcarbonyl}ethylene} (3b) was synthesized as the lipophilic and polymeric model of 1‐{N‐[2‐(2‐acetylamino‐2‐deoxy‐3‐O‐D‐glucopyranosyl)propionyl]‐L‐alanylamino}glutamic acid (1) to the minimum required structure for the eimmunoadjuvant activity of bacterial cell wall. N‐[2‐(6‐O‐acryloyl‐1,2‐O‐isopropylidene‐α‐D‐3‐O‐glucofuranosyl)propionyl]‐L‐alanine benzyl ester (6) was prepared as a key monomer in the synthesis. The homopolymerization of this monomer was carried out in benzene at 50°C using 2, 2′‐azoisobutyronitrile as radical initiator to give polymer 7. From the results of copolymerization with styrene, the values of Q and e for the acryloyl type monomer 6 were estimated to be 2,0 and 0,11, respectively. The removal of isopropylidene and benzyl protecting groups from homopolymer 7 was carried out by acidic treatment with trifluoroacetic acid/water (vol. ratio 6:1) and by catalytic hydrogenolysis with palladium carbon in acetone, respectively, to afford the homopolymer 3b.