Lambda 400 spectrometer

All solution‐phase reactions were conducted under an argon atmosphere. ¹H NMR spectra were obtained at 300 MHz on a JEOL Al300 spectrometer and at 400 MHz on a JEOL Lambda 400 spectrometer with tetramethylsilane (TMS) as an internal standard (δ 0.0) in CDCl₃. ³¹P NMR spectra were obtained at 162.0 MHz on a JEOL Lambda 400 spectrometer with 85 % H₃PO₄ (δ 0.0) as an external standard. ¹⁹F NMR spectra were obtained at 376.3 MHz on a JEOL Lambda 400 spectrometer. Mass spectra were recorded on a JMS‐700 spectrometer (JEOL) with trifluoroacetic acid as an external standard (δ−76.5). Mass spectra were recorded on a 910‐MS FTMS system (Varian) or a Voyager System 4327 (Applied Biosystems). Analytical TLC was performed on Merck Kieselgel 60‐F254 plates. Silica gel column chromatography was carried out using silica gel 60 n (63–210 μm or 40–50 μm) as a neutral silica gel, and Chromatorex NH‐DM1020 as an NH silica gel. Gel filtration chromatography was conducted using Sephadex^® LH‐20. RP‐HPLC was carried out using a μBondasphere 5 μm C18, 100 Å, 3.9 mm × 150 mm (Waters). Organic solvents were purified and dried according to the appropriate procedures. Anomeric ratio was calculated from relative peak areas in ¹⁹F NMR and ³¹P NMR.