Sodium Sulfate → HCID 86701262, compound

Participants

Reaction Conditions

Reaction Steps

A round bottom flask was charged with (3S,6S,7R,8R)-3-(tert-butoxycarbonyl-amino)-8-(2-hydroxyethyl)-6-methyl-4,9-dioxo-1,5-dioxonan-7-yl isobutyrate (200 mg, 0.48 mmol), Proton Sponge™ (700 mg, 4.05 mmol), Na2SO4 in CH2Cl2 (10 mL) at 0° C. To the resulting suspension was added trimethyloxonium tetrafluoroborate (Me3OBF4, 320 mg, 2.16 mmol), and the suspension was warmed to room temperature (about 22° C.) and stirred for 5 h. The mixture was diluted with EtOAc, filtered, and the filtrate was washed successively with water and 1M NaHSO4. The organics were dried over Na2SO4, filtered, and the filtrate was concentrated under reduced pressure. Purification of the crude product via column chromatography (hexanes/EtOAc gradient) afforded the title compound (140 mg, 71%) as a clear oil: 1H NMR (300 MHz, CDCl3) δ 5.41-5.16 (m, J=0.9 Hz, 2H), 5.06 (t, J=9.9 Hz, 1H), 4.94-4.73 (m, 2H), 3.69-3.52 (m, 1H), 3.42-3.27 (m, 2H), 3.26 (s, J=0.9 Hz, 3H), 2.80-2.67 (m, 1H), 2.60 (dt, J=13.9, 7.0 Hz, 1H), 2.08-1.86 (m, 1H), 1.66-1.55 (m, 1H), 1.45 (s, 9H), 1.27 (d, J=6.3 Hz, 3H), 1.20 (d, J=7.0 Hz, 6H); ESIMS m/z 454 ([M+Na]+).

Provenance & Evidence