Stereoselective synthesis of optically active β-lactams, potential inhibitors of pilus assembly in pathogenic bacteria

matrix presented Optically active β-lactams 3 are obtained in excellent yields (up to 93%) and with complete stereoselectivity from Meldrum's acid derivatives 1 and Δ²-thlazolines 2. A selective reduction to aldehydes 5 (R = Ar or CH₂Ar) was then accomplished by using DIBAL-H. This rigid framework, with stereochemistry different than that of penicillin, is designed to be a suitable scaffold for the development of compounds inhibiting pilus formation in uropathogenic Escherichia coli.