Stereoselective synthesis of optically active bicyclic β-lactam carboxylic acids that target pilus biogenesis in pathogenic bacteriaElectronic supplementary information (ESI) available: 13C NMR spectra of 7(a–g), 10–14, 16(a and d) and 17(a–b). See http://www.rsc.org/suppdata/ob/b2/b210551a/