Soluble polymer-supported convergent parallel library synthesisElectronic supplementary information (ESI) available: detailed synthetic procedures for synthesis of 5b–7, PEG-supported synthesis of L1a--i and L2a–i, purification of L4, 1H-NMR spectra and LC/MS and HR-MALDIMS data of selected hexapeptide from L4. See http://www.rsc.org/suppdata/cc/b2/b210696e/