反应详情

To a solution of the oxime 26 (2.70 g, 7.59 mM) in MeOH (50 ml), containing methyl orange (2 mg) as as indicator, was added a solution of NaBH3CN (0.52 g, 8.4 mM) in MeOH (20 ml), and a solution of 2N HCl, simultaneously, at such a rate to maintain a pH of 3 to 4. The reaction was stirred for 3 hours at room temperature, acidified to pH 1 and concentrated in vacuo. The residue was diluted with H2O (100 ml), adjusted to pH 8.5 with 5N NaOH, and extracted with EtOAc. The extracts were combined, dried (Na2SO4), filtered and concentrated in vacuo. The residue was chromatographed on Merck Silica Gel 60 (90 g, 230-400 mesh) with EtOAc:MeOH (9:1) as eluent. Crystallization from Et2O afforded pure 38 (1.64 g, 60%) as a white solid, mp=91°-93°. MS, m/e 357(M+).

1. concentrationconcentrated in vacuo
2. additionThe residue was diluted with H2O (100 ml)
3. extractionextracted with EtOAc
4. dry with materialdried (Na2SO4)
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe residue was chromatographed on Merck Silica Gel 60 (90 g, 230-400 mesh) with EtOAc:MeOH (9:1) as eluent
8. customCrystallization from Et2O afforded pure 38 (1.64 g, 60%) as a white solid, mp=91°-93°