Apex ultra 7.0t spectrometer

ORD data were measured using a JASCO P-2000 spectrometer in CH₃OH. UV and ECD spectra were performed using a Perkin-Elmer model 241 spectrophotometer and a JASCO J-715 CD spectrometer, respectively. VCD spectra, including the corresponding IR spectra, were acquired using a BioTools ChiralIR-2X spectrophotometer. NMR data with TMS as an internal standard were measured using Bruker Avance-Ⅲ 600 MHz NMR spectrometer. HRESIMS data were obtained from a Bruker apex-ultra 7.0T spectrometer. Semipreparative HPLC, using Waters (XBridge OBD, 5 μm, 10 × 250 mm) and Daicel (Chiralpak IB, 5 μm, 10 × 250 mm) columns, was carried out on a Shimadzu LC-20AT system with a SPD-M20A photodiode array detector. Column chromatography was performed on Silica gel 200–300 and 300–400 mesh, and Sephadex LH-20 18−110 μm.

Chlorothalonil was purchased from Xiangtan Huayuan Fine-Chem Co. Ltd. (Xiangtan, China). 4-Dimethylaminopyridine (DMAP), N,N-dicyclohexylcarbodiimide (DCC) and carboxylic acids were purchased from J & K Chemical Ltd. (Beijing, China). Other reagents and solvents were obtained locally. All solvents were dried, and redistilled before use. The water used was redistilled and ion-free. Analytical thin-layer chromatography (TLC) was performed on silica gel GF₂₅₄. Column chromatographic (CC) purification was carried out using silica gel (200–300 mesh). Above silica gel was obtained from Qingdao Haiyang Chemical Co., Ltd. (Qingdao, China). The melting points of the synthetic derivatives were determined on an X-6 apparatus (Beijing Tech., Beijing, China) and are uncorrected. Nuclear magnetic resonance (NMR) experiments were performed on an Avance 400/500 MHz instrument (Bruker, Bremerhaven, Germany). HR-MS (ESI) were obtained using a Bruker Apex-Ultra 7.0 T spectrometer. Reaction progress was monitored by thin-layer chromatography on silica gel GF-254 with detection by UV light.

Optical rotations were measured on a Perkin-Elmer 341 spectropolarimeter (PerkinElmer, Waltham, MA, USA). UV spectra were measured on an UV-210 spectrometer (Analytikjena, Jena, Germany). IR Spectra were acquired on a PerkinElmer 577 instrument (PerkinElmer, Waltham, MA, USA). NMR Spectra were recorded on a Bruker AM-600 spectrometer (Bruker, Fllanden, Switzerland). HR-MS Spectra were recorded on a Bruker apex-ultra 7.0T spectrometer (Bruker, Billerica, MA, USA). Column chromatography (CC) were conducted over silica gel (SiO₂; 200–300 mesh; Yantai Zhi Fu chemical Co., Yantai, China), and Sephadex LH-20 gel (25–100 μm, GE Healthcare Co., Ltd., Uppsala, Sweden). TLC were conducted with silica gel GF₂₅₄ plates (Yantai Zhi Fu chemical Co., Ltd., Yantai, China).