Direct drive 500

Optical rotation was measured using an AutoPol IV polarimeter at 589 nm; UV absorption was measured by Agilent Cary 60 UV-Vis spectrophotometer. The IR spectrum was recorded with a PerkinElmer Spectrum Two equipped with a UATR (single reflection diamond) sample introduction system; NMR spectra were recorded at 298K on Varian Inova 400 or Varian Direct Drive 500 spectrometers. Chemical shifts are reported with the use of the residual MeOH-d₄ signal (δ_H 3.31 ppm and δ_C 49.2 ppm) as internal standards. The ¹H and ¹³C NMR assignments were supported by gCOSY, gHSQC/gHMQC, and gHMBC spectra. MPLC was performed using a Combiflash Rf 200i MPLC, using ELSD and UV detection with a RediSepRf 80 g silica column. Semi-preparative and analytical high performance liquid chromatography (HPLC) was performed on a Shimadzu LC-20 AT system equipped with an evaporative light scattering detector (ELSD) and an ultraviolet detector. Normal phase was completed with a gradient of hexanes to EtOAc on a semi-preparative Phenomenex silica column (10 μm, 100 Å, 250 × 10 mm) using ELSD and UV detection. Reversed phase HPLC was completed with a gradient of H₂O to either ACN or MeOH on a semi-preparative Phenomenex C18 column (10 μm, 100 Å, 250× 10 mm), or on an analytical Phenomenex C18 column (5 μm, 100 Å, 250 × 4.6 mm).