1H NMR and 13C NMR spectra (δ, in ppm; J, in Hz; relative to internal TMS in CDCl3 solns. at 20°C) were recorded on Bruker WH-250 and Bruker Advance DPX- 400 spectrometers, MS (electron impact mass spectrum; m/z in % of base peak) on a Nermag R-10-10C spectrometer. Melti...
(Varian, Willich, Germany); 1H-NMR (600 MHz), 13C-NMR (151 MHz): Agilent Technologies (Waldbronn, Germany) 600/54 premium spectrometer: δ in ppm related to tetramethylsilane; coupling constants are given with 0.5 Hz resolution; 1H- and 13C-NMR spectra are shown in the Supplementary ...