Sodium Thiosulfate → (4R,7S)-4-azido-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-3-one

Participants

Reaction Steps

To a solution of (3S,4R,7S)-4-azido-7-(1-methyl-4-nitro-1H-pyrazol-5-yl)oxepan-3-ol (1.4 g, 4.96 mmol, intermediate 90) in DCM (35 mL) was added Dess-Martin peridionane (2.52 g, 5.96 mmol) and the mixture stirred at room temperature for 2 hr. Aqueous saturated NaHCO3 (60 mL) and 20% sodium thiosulfate solution (50 mL) were added and the reaction mixture was stirred for 30 min until full dissolution of salts was observed. The organic layer was separated, dried over MgSO4 and solvents removed under reduced pressure. Purification via silica gel column chromatography (0-40% EtOAc/isoHexane) gave (4R,7S)-4-azido-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-3-one as an off-white solid (1.1 g, 82%). 1H NMR (400 MHz, CDCl3) δ 8.05 (s, 1H), 5.38 (dd, J=10.2, 2.7 Hz, 1H), 4.62-4.49 (m, 2H), 4.31-4.22 (m, 1H), 4.08 (s, 3H), 2.31-2.17 (m, 3H), 2.15-2.04 (m, 1H).

Provenance & Evidence