反应详情

To a solution of 2-methyl-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-4-one (65 mg, 0.26 mmol) in THF (1 mL) under nitrogen cooled to −78° C. was added dropwise a solution of L-selectride (1 M in THF, 0.28 mL, 0.28 mmol). After 1 hr the mixture was quenched with MeOH (1 mL) and warmed to room temperature. EtOAc (10 mL) and brine (10 mL) were added and the layers separated. The aqueous layer was extracted with EtOAc (3×10 mL) and the combined organic layers were washed with brine (10 mL), separated, dried over Na2SO4 and concentrated under reduced pressure. Purification via silica gel column chromatography (0-100% EtOAc/isohexane) gave 2-methyl-7-(2-methyl-4-nitro-pyrazol-3-yl)oxepan-4-ol as a colourless solid (54 mg, 81%). 1H NMR (400 MHz, CDCl3) δ 8.01 (2s, 1H), 5.63-5.59 and 5.56-5.50 (2m, 1H), 4.26-4.01 (m, 5H), 3.88-3.73 (m, 1H), 2.21-1.72 (m, 4H), 1.28-1.23 (m, 3H), 0.99-0.81 (m, 2H).

1. customAfter 1 hr the mixture was quenched with MeOH (1 mL)
2. additionEtOAc (10 mL) and brine (10 mL) were added
3. customthe layers separated
4. extractionThe aqueous layer was extracted with EtOAc (3×10 mL)
5. washthe combined organic layers were washed with brine (10 mL)
6. customseparated
7. dry with materialdried over Na2SO4
8. concentrationconcentrated under reduced pressure
9. customPurification via silica gel column chromatography (0-100% EtOAc/isohexane)