To a solution of 4-[1-(4-pentafluoroethyloxy-phenyl)-1H-[1,2,4]triazol-3-yl]-benzaldehyde O-((2S,3R,4R,5S,6S)-4-ethoxy-3,5-dimethoxy-6-methyl-tetrahydropyran-2-yl)-oxime (P-1; 257 milligrams (mg), 0.429 millimoles (mmol)) in 190 proof ethyl alcohol (EtOH; 10 milliliters (mL)) at room temperature was added pyridine borane complex (200 microliters (μL), 1.99 mmol) in one portion. 3 N Hydrochloric acid (HCl; 1.4 mL) was then added dropwise. When the addition was complete, the mixture stirred at room temperature for 23 hours (h). The mixture was then diluted with EtOH/water (H2O) and treated with saturated sodium bicarbonate (NaHCO3). The resulting aqueous mixture was extracted with ethyl acetate (EtOAc; 2×). The organic extracts were combined, dried, washed with brine and dried with anhydrous sodium sulfate (Na2SO4). The solvent was evaporated at room temperature under vacuum. The resulting crude material was purified by silica gel chromatography (eluting with 50% EtOAc in Hexane). The title product (164 mg, 63%) was isolated as a white sticky solid: 1H NMR (300 MHz, CDCl3) δ 8.60 (s, 1H), 8.22-8.16 (m, 2H), 7.87-7.80 (m, 2H), 7.50 (d, J=8.2 Hz, 2H), 7.46-7.38 (m, 2H), 6.04 (s, 1H), 5.01 (d, J=1.4 Hz, 1H), 4.18 (s, 2H), 3.84-3.28 (m, 12H), 3.11 (dd, J=12.0, 6.5 Hz, 1H), 1.30 (ddd, J=20.9, 10.3, 4.6 Hz, 6H); ESIMS m/z 603 (M+H).
