hours, 50% AcOH/TFE was found to reduce the "stickiness" of the beads to plastic microtiter plates and thus make the protocol more convenient). The products were released from the beads using trifluoroacetic acid (TFA) and analyzed by liquid chromatography/mass spectrometry (LC-MS). As shown in Figure , macrocycle MP1 was formed in nearly quantitative yield. NMR analysis of the crude material (Supplementary Figure1) confirmed the high purity of the material as well as its structure. Indeed, when MP1