Diastereoselective Synthesis of Potent Antimalarial

Fifteen novel β-lactams bearing N-ethyl tert-butyl carbamate group 5a-o and fifteen N-(2- aminoethyl) β-lactams 6a-o were synthesized by [2+2] ketene-imine cycloaddition reaction (Staudinger). The cycloaddition reaction was found to be totally diastereoselective leading exclusively to theformation of cis-β-lactam derivatives. These newly synthesized β-lactams were evaluated for their antimalarial activity against p. falciparum K14 resistant strain and showed good to excellent EC50 values. Of the thirty β-lactams tested, 5 h, 6a and 6c showed IC50 < 20 µM while 5b, 5c, 5e, 5f, 5g, 5i, 5j, 6d, 6g and 6h exhibited IC50