CD spectra were measured with a JASCO J-810 spectropolarimeter.
IR spectra were obtained on a Thermo Scientific Nicolet 6700 FT-IR spectrometer.
NMR spectra were run at room temperature on Bruker Avance DRX-400 or 800 MHz spectrometers, and the data were
processed using MestReNova 6.0 software (Mestrelab Research SL, Santiago de Compostela, Spain).