General Experimental Procedures

Polymerase chain reaction (PCR) amplifications were reacted by FlexCycler PCR. Optical rotations were measured with a JASCO P-2000 polarimeter. UV spectra were recorded on a JASCO V-530 UV–vis spectrophotometer, and experimental ECD spectra were measured on a JASCO J-815 spectropolarimeter. IR spectra were obtained on a JASCO FT/IR-4600 Fourier transform infrared spectrometer. 1D and 2D NMR spectra were performed on a JEOL JNM-ECS 400 MHz NMR spectrometer (¹H, 400 MHz; ¹³C, 100 MHz), Varian Mercury Plus 400 MHz FT-NMR (¹H, 400 MHz; ¹³C, 100 MHz), and Varian VNMRS 600 MHz FT-NMR (¹H, 600 MHz; ¹³C, 150 MHz) in CDCl₃, CD₃OD, and CD₃COCD₃, respectively. Mass spectra were obtained from a Waters 2695 separation module (ESI-MS) and Bruker FT-MS SolariX (HR-ESI-MS). Column chromatography was carried out on silica gel 60 (0.063–0.200 mm and 0.040–0.063 mm, Merck) and Sephadex LH-20 (Fine Chemicals AB, Uppsala, Pharmacia). Thin-layer chromatography (TLC) analyses were performed using silica gel 60, F254, and RP-18, F254S (0.20 nm, Merck, Germany). Semi-preparative HPLC was performed on Shimadzu LC-10 AD, Shimadzu LC-20AT, or Jasco PU-980 pumps, an SPD-M10A diode array, SPD-10A UV–vis or UV-970 UV–vis detectors, and SCL-10A or CBM-20A controllers with Luna phenyl-hexyl, 100 Å, 250 × 10 mm, Phenomenex or Luna CN, 100 Å, 250 × 10 mm, Phenomenex columns.