A practical and efficient preparation of the releasable naphthosultam sidechain of a novel anti-MRSA carbapenem

A practical large-scale synthesis of the naphthosultam-based side chain of the anti-MRSA antibiotic 1 has been achieved in 29% overall yield over seve n steps from l-methylnaphthalene. The synthesis was completed without the u se of protecting groups, featuring a novel naphthosultam annelation, a chem oselective acid-catalyzed triflation, and the use of a novel naphthosultam dianion to effect functionalization through benzylic metalation.