Synthese De La N-acetylmuramyl (OXO-14C-propyl)-L-alanyl-D-isoglutamine (MDP-14C)

SYNTHESIS OF N-ACETYLMURAMYL (14C-OXOPROPYL)-L-ALANYL-D- ISOGLUTAMINE (14C - MDP) Condensation of (1-14C) DL-2-bromopropionic acid with benzyl 2-acetamido-4,6-0-benzylidene-2-deoxy-β-D-glucopyranoside 7 in presence of sodium hydride gave 50 % of crystalline compound 3, having the correct stereochemistry of natural muramic acid. The latter, in presence of Woodward's reagent, reacted with L-alanyl-D-isoglutamine benzyl ester hydrochloride, leading to compound 4. Removal of benzylidene and benzyl groups by successive acetic acid exposure and hydrogenolysis gave rise to 2-acetamido-2-deoxy-3-0 (2-D-(14CO) propionyl-L-alanyl-D-isoglutamine)-D-glucopyranose (14C-MDP) Specific activity : 42 mCi/mMole in a 10 % overall yield based on sodium (1-14C) propionate.