Analysis methods 1 H and C NMR spectra were recorded on a Bruker Avance 400 (400.1 MHz for 1 H and 101 MHz for 13 C) without additional internal standard. Chemical shifts are reported in δ values (ppm) and are calibrated against residual solvent signal. The following abbreviations were used to define the multiplicities: s, singlet; d, doublet; t, triplet; q, quartet; m, multiplet. Reverse phase UPLC was carried out on an Agilent 1290 Infinity II High-Throughput System, equipped with a Kinetex 5 µM XB-C18 100 Å, LC column (50 × 2.1 mm). Chiral HPLC analysis was performed on an Agilent 1200 Series Purification System equipped with a Chiralpak IE column.