反応 #44331

反応方程式

Isoamyl nitrite

[(2R,3R,4R,5R)-3-,4-diacetyloxy-5-(2-amino-6-chloropurin-9-yl)oxolan-2-yl]methy 1 acetate

[(2R,3R,4R,5R)-3,4-diacetyloxy-5-(2-amino-6-chloropurin-9-yl)oxolan-2-yl]methyl acetate

I2

CH2I2

Na2S2O3

→

[(2R,3R,4R,5R)-3,4-diacetyloxy-5-(6-chloro-2-iodopurin-9-yl)oxolan-2-yl]methyl acetate

溶媒

THF

反応条件

後処理

1. 1
   温度The mixture was heated
2. 2
   温度under reflux for 45 minutes
3. 3
   その他This step removed the reddish color
4. 4
   抽出The aqueous layer was extracted 3× with chloroform, which
5. 5
   乾燥dried over MgSO4
6. 6
   濃縮concentrated under reduced pressure
7. 7
   その他The product was then purified over a silica gel column
8. 8
   その他to collect [(2R,3R,4R,5R)-3,4-diacetyloxy-5-(6-chloro-2-iodopurin-9-yl)oxolan-2-yl]methyl acetate (6.4) (80% crystallized from EtOH)

実験手順

Isoamyl nitrite (5 mL, 37 mmol) was added to a mixture of 5.12 g (12 mmol) [(2R,3R,4R,5R)-3-,4-diacetyloxy-5-(2-amino-6-chloropurin-9-yl)oxolan-2-yl]methy 1 acetate (6.3), I2 (3.04 g, 12 mmol), CH2I2 (10 mL, 124 mmol), and CuI (2.4 g, 12.6 mmol) in THF (60 mL). The mixture was heated under reflux for 45 minutes and then allowed to cool to room temperature. To this solution was added 100 ml of saturated Na2S2O3. This step removed the reddish color. The aqueous layer was extracted 3× with chloroform, which was pooled, dried over MgSO4, and concentrated under reduced pressure. The product was then purified over a silica gel column using CHCl3-MeOH (98:2) to collect [(2R,3R,4R,5R)-3,4-diacetyloxy-5-(6-chloro-2-iodopurin-9-yl)oxolan-2-yl]methyl acetate (6.4) (80% crystallized from EtOH). 1H NMR (300 MHz, CDCl3) 8.20 (s, 1H H-8), 6.17 (d, J=5.41 Hz, 1H, H-1), 5.75 (t, J=5.39 Hz, 1H, H-2), 5.56 (t, J=5.40 Hz, 1H, 1H-3), 4.38 (m, 3H, 1H-4,5), 2.14 (s, 1H, Ac), 2.11 (s, 1H, Ac), 2.10 (s, 1H, Ac).

出典