Boron trifluoride etherate → diethyl (((2S,3S,4R,5R,6S)-3,4,5-tris(benzyloxy)-6-methyltetrahydro-2H-pyran-2-yl)methyl)phosphonate

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Reaction Conditions

Reaction Steps

Boron trifluoride diethyl etherate (0.079 mL, 0.644 mmol, commercially available from Sigma Aldrich) and triethylsilane (0.103 mL, 0.644 mmol, Sigma Aldrich) were added to a stirred solution of diethyl (((2S,3S,4R,5R,6S)-3,4,5-tris(benzyloxy)-2-hydroxy-6-methyltetrahydro-2H-pyran-2-yl)methyl)phosphonate (0.251 g, 0.429 mmol) in acetonitrile (2 mL) at 0° C. under an argon atmosphere. The reaction mixture was then stirred at 0° C. for 5 h. The reaction mixture was next partitioned between EtOAc and saturated aqueous sodium bicarbonate. The organic layer was separated, dried over anhydrous magnesium sulfate, filtered, and concentrated in vacuo. The resulting oil was purified by silica gel chromatography (30 to 100% EtOAc/hexanes gradient) to give diethyl (((2S,3S,4R,5R,6S)-3,4,5-tris(benzyloxy)-6-methyltetrahydro-2H-pyran-2-yl)methyl)phosphonate as a colorless oil (0.220 g, 90% yield). 1H NMR (400 MHz, CDCl3): δ ppm 1.14 (d, J=6.26 Hz, 3 H) 1.26 (td, J=7.04, 1.96 Hz, 6 H) 1.92 (td, J=15.75, 9.78 Hz, 1 H) 2.29 (ddd, J=19.95, 15.36, 1.47 Hz, 1 H) 3.53 (q, J=6.39 Hz, 1H) 3.56-3.70 (m, 4 H) 3.98-4.11 (m, 4 H) 4.63-4.77 (m, 4 H) 4.97 (dd, J=11.44, 1.86 Hz, 2 H) 7.26-7.39 (m, 15 H).

Provenance & Evidence