An efficient synthesis of the side chain intermediate of BO-2502A, a new 1β-methyl carbapenem, via diastereoselective lactamization as a key step

Abstract The BO-2502A side chain intermediate 3 was prepared via the diastereoselective lactamization of the in situ prepared amino diacid anhydride 14 as a key step. The diastereoselectivity of this step was found to be 53:1 (96% de).