反应 #12045

反应方程式

6-acetyl-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

(4R,9aR)-6-(2-hydroxy-ethoxymethyl)-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

intermediate b

(4R,9aR)-6-(2-hydroxy-ethoxymethyl)-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

borane dimethylsulfide

→

6-((1S)-1-hydroxy-ethyl)-(4R,9aR)-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

溶剂

THF

THF

反应条件

后处理

1. 1
   workup.STIRRINGA solution was stirred at 0° C. for 3 hours
2. 2
   其他quenched with methanol
3. 3
   其他partitioned between aqueous ammonium chloride and EtOAc
4. 4
   其他The phases were separated
5. 5
   洗涤the organic layer was washed with brine
6. 6
   干燥dried (MgSO4)
7. 7
   浓缩concentrated in vacuo
8. 8
   其他The residue was purified by column chromatography [SiO2; isohexane-ethyl acetate (1:1)]

实验过程

To a stirred solution of (R)-Me-CBS-oxazaborolidine (770 μl, 1M in toluene) in THF (3 ml) was added borane-dimethylsulfide (770 μl, 2M in THF) at 0° C. under nitrogen. A solution was stirred for 5 mins, then 6-acetyl-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester (Example 34, intermediate b) (255 mg) in THF (2.5 ml) was added dropwise over 45 mins. A solution was stirred at 0° C. for 3 hours, quenched with methanol and partitioned between aqueous ammonium chloride and EtOAc. The phases were separated and the organic layer was washed with brine, dried (MgSO4) and concentrated in vacuo. The residue was purified by column chromatography [SiO2; isohexane-ethyl acetate (1:1)] to afford 6-((1S)-1-hydroxy-ethyl)-(4R,9aR)-4-methyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester (185 mg) as a colorless oil: 1H NMR (400 MHz, CDCl3): 7.16 (1H, d, J 7 Hz), 6.35 (1H, d, J 7 Hz), 4.37–4.31 (1H, br s), 4.31–4.19 (1H, br s), 4.09–3.95 (1H, m), 3.95–3.85 (1H, m), 3.13–2.94 (2H, m), 2.79–2.55 (1H, br s), 2.54 (1H, dd, J 6 and 16 Hz), 1.48 (9H, s), 1.44 (3H, d, J 6.5 Hz) and 1.24 (3H, d, J 6.5 HZ); MS (ES) 334.3 (MH+).

来源