Reaktion #517575

Reaktionsgleichung

Isoamyl nitrite

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

Lösungsmittel

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe mixture was heated
2. 2
   Temperaturunder reflux for 45 minutes
3. 3
   Sonstigeremoved the reddish color due to iodine
4. 4
   ExtraktionThe aqueous was extracted 3× with chloroform, which
5. 5
   Trocknendried over MgSO4
6. 6
   Einengenconcentrated under reduced pressure
7. 7
   SonstigeThe product was then purified over a silica gel column
8. 8
   Sonstigeto 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)

Vorschrift

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]methyl 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 sat. Na2S2O3 which removed the reddish color due to iodine. The aqueous 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) δ8.20 (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, H-3′), 4.38 (m, 3H, H-4′,5′), 2.14 (s, 1H, Ac), 2.11 (s, 1H, Ac), 2.10 (s, 1H, Ac).

Quelle