Reacción #44331

Ecuación de reacción

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

Disolventes

THF

Condiciones de reacción

Tratamiento posterior

1. 1
   TemperaturaThe mixture was heated
2. 2
   Temperaturaunder reflux for 45 minutes
3. 3
   OtroThis step removed the reddish color
4. 4
   ExtracciónThe aqueous layer was extracted 3× with chloroform, which
5. 5
   Secadodried over MgSO4
6. 6
   Concentraciónconcentrated under reduced pressure
7. 7
   OtroThe product was then purified over a silica gel column
8. 8
   Otroto 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)

Procedimiento

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).

Fuente