Xevo g2 q tof spectrometer

Specific rotations were measured by an SGW-1 automatic polarimeter (Shanghai Jing Ke Industrial Co., Ltd., Shanghai, China). The NMR spectra were recorded on a Bruker Avance III HD-400 NMR spectrometer. HRESIMS spectra were obtained on a Waters Xevo G2 Q-TOF spectrometer fitted with an ESI source (Bruker Corporation, Karlsruhe, Germany). Semi-preparative high-performance liquid chromatography (HPLC) was undertaken on a Shimadzu LC-6AD pump (Shimadzu Co., Kyoto, Japan) using a UV detector, and a YMC-Pack ODS-A HPLC column (semipreparative, 250 × 10 mm, S-5 μm, 12 nm, YMC Co., Ltd., Kyoto, Japan) was used for separation.

The reactions were carried out in oven-dried glassware. All reactions were carried out under anhydrous conditions with freshly distilled solvents under a positive pressure of argon unless otherwise noted. Umemoto’s reagent refers to S-(trifluoromethyl)dibenzothiophenium tetrafluoroborate. The reactions were monitored using thin-layer chromatography (TLC) on silica-gel-coated aluminum plates (60 F₂₅₄, E. Merck). Column chromatography was performed on silica gel (200–300 mesh). Gel filtration was performed on Sephadex LH-20 (Pharmacia). Optical rotations were obtained on a Hanon P850 Automatic Polarimeter. Experiments under ultraviolet (UV) irradiation were carried out using a safe and stable mercury lamp spotlight system purchased from Beijing Zhongjiao Jinyuan Technology Co., Ltd. (Item No. CEL-M500). ¹H NMR spectra were recorded at room temperature for solutions in CDCl₃ or D₂O with Avance III-400 or III-600 instruments (Bruker), and the chemical shifts were referenced to the peak for TMS (0 ppm, CDCl₃) or external CH₃OH (3.34 ppm, D₂O). ¹³C NMR spectra were recorded using the same NMR spectrometers, and the chemical shifts were reported relative to the internal CDCl₃ (δ = 77.16 ppm) or external CH₃OH (49.70 ppm, D₂O). High-resolution mass spectrometry (HRMS) experiments were performed on a Waters Xevo G2 Q-TOF spectrometer or a Bruker APEX IV FTMS instrument.