P 2200 polarimeter

Optical rotations were obtained with a JASCO P-2200 polarimeter. NMR spectra were recorded in C₆D₆, CD₃OD and CDCl₃ using a JNM-EX 270 FT-NMR spectrometer (JEOL, ¹H NMR: 270 MHz) and AMX 500 Bruker system (¹H NMR: 500 MHz, ¹³C NMR: 126 MHz). Assignment of H and C was performed by obtaining ¹H NMR, ¹³C NMR (referenced for C₆D₆, CD₃OD and CDCl₃ at δ_H 7.16, 3.31 and 7.24, and δ_C 128.4, 49.2 and 77.2, respectively), COSY, HSQC, HMBC, and NOESY spectra. FD-MS analysis was performed on a JMS-T100GCV (JEOL) instrument. Chromatographic analysis was performed using an HPLC system (InertSustain, A_210max nm) equipped with a Shisheido Capcell park C18 column (4.6 × 250 nm, 5 µm, 2 mL/min, MeOH-H₂O, 80:20) and a Cadenza CK-C18 column (6 × 250 nm, 3 µm, 2 mL/min, MeOH-H₂O, 80:20). All moisture-sensitive reactions were performed under a nitrogen gas atmosphere. All chemicals used in the study were of analytical grade and purchased from Sigma–Aldrich, Tokyo, Japan, Kanto Chemical Co., Inc, Tokyo, Japan, and Cayman Chemical, Ann Arbor, MI, USA.

NMR spectra were recorded on an Avance (400 MHz) spectrometer (Bruker Corporation, Billerica, MA, USA). ¹H and ¹³C NMR chemical shifts were referenced to the CD₃OD solvent peaks δ_H 3.31 and δ_C 49.15 (Wako, Osaka, Japan). HRESI-MS spectra were measured on an Exactive Plus (Thermo Fisher Scientific Inc., Waltham, MA, USA). ESIMS/MS spectra were measured on a TripleTOF 4600 (AB Sciex Pte. Ltd., Tokyo, Japan) in the positive mode. Optical rotation was determined on a P-2200 polarimeter (JASCO Corporation, Tokyo, Japan) in CH₃OH. UV spectra were recorded using a V-630 spectrophotometer (JASCO). IR spectra were measured on a Nicolet6700 spectrometer (Thermo Fisher Scientific Inc.).

¹H NMR and ¹³C NMR spectra were recorded on a JEOL (Akishima, Japan) ECS-400 spectrometer at 400 and 100 MHz, respectively. The ¹H NMR chemical shifts were referenced to the signals of Me₄Si as the internal standard (0.00 ppm in CDCl₃ and HDO, and 4.80 ppm in D₂O). The ¹³C NMR chemical shifts were referenced to the signals of the solvent [δ_C (CDCl₃) 77.0] and native scale (D₂O). Assignments were aided by COSY, TOCSY, and ¹H–¹³C correlation experiments. All reactions were monitored by TLC using a glass plate coated with silica gel 60F254 (0.2 mm thickness, Merck KGaA, Darmstadt, Germany). Silica gel column chromatography was performed using 60N silica gel (Kanto Chemical, Tokyo, Japan). Anhydrous solvents (superdehydrated grade) were purchased from FUJIFILM Wako Pure Chemical Corp (Osaka, Japan). Optical rotations were measured with a JASCO (Hachioji, Japan) P2200 polarimeter. High resolution mass spectra (HRMS) were recorded on Bruker (Billerica, MA, USA) micrOTOF II and Thermo Scientific (Waltham, MA, USA) Exactive Plus spectrometers using electrospray ionization in acetonitrile or methanol. MALDI-TOF MS was carried out using an Autoflex Speed mass spectrometer (Billerica, MA, USA).

The optical rotations were recorded on a JASCO P-2200 polarimeter. The UV spectra were recorded on a JASCO Ubest-55 spectrophotometer. The IR spectra were recorded on a JASCO FT/IR-420 spectrophotometer. The ECD spectra were recorded on a JASCO J-1500 spectropolarimeter. ¹H and ¹³C NMR spectra were recorded on a Bruker Avance II 600 MHz NMR spectrometer equipped with a cryoplatform using 3.0 mm micro cells (Shigemi Co., Ltd., Tokyo, Japan) for CD₃OD. The 3.35 ppm resonance of residual CD₂HOD in CD₃OD was used as the internal references for ¹H NMR spectra. The 49.8 ppm resonances of CD₃OD were used as the internal reference for the ¹³C NMR spectra. The MS spectra were recorded on a JEOL JMS-T100LP spectrometer. The flash column chromatography was performed with a Biotage Isolera flash purification system.

Ultraviolet-visible spectroscopic analysis was conducted in a UV-1900-UV-Visible spectrophotometer from Shimadzu (Japan). Chiral gas chromatography (GC) was performed on a GC-14B equipped with flame ionization detector and a CP-Chirasil-Dex-CB column (Varian 0.32 mm × 0.25 μm × 50 m) using He carrier gas (5 mL min⁻¹, head pressure: 274 kPa, injector: 180 °C, detector: 180 °C) (Shimadzu, Japan). The morphology and energy dispersive X-ray spectroscopy (EDX) analysis were studied by Bench-top Scanning Electron Microscope proX supplied by Phenom-World (Netherlands). Thermo Gravimetric Analysis (TGA) was performed on TG-DTA, DTG-60 (Shimadzu, Japan). The optical rotation value was measured by JASCO P-2200 Polarimeter with a 10 cm path-length cell. The ¹H-NMR analysis was performed on a Bruker Biospin AVANCE III 400 spectrometer at 400 MHz in CDCl₃.