Réaction #302904

Équation de réaction

1-(3-O-Acetyl-2,5-dideoxy-5-iodo-β-D-threo-pentofuranosyl)-thymine

Ac2O

pyridine

→

4′-ethynyl-d4T

7

Rendement 93.0%

1-(3-O-Acetyl-2,5-dideoxy-5-iodo-β-D-threo-pentofuranosyl)-thymine

Rendement 93.0%

Conditions de réaction

Traitement

1. 1
   Autrewas prepared
2. 2
   AutreThe reaction mixture was partitioned between CHCl3/saturated aqueous NaHCO3 (250 mL×3/50 mL)

Mode opératoire

TKD-4-114 (2′,3′-didehydro-3′-deoxy-4′-ethynylthymidine, 4′-ethynyl-d4T) was synthesized by a series of reactions shown in Scheme B, starting from compound 6 which was prepared according to the published procedure: B. V. Joshi and C. B. Reese, Tetrahedron Lett., 32, 2371-2374 (1992). 1-(3-O-Acetyl-2,5-dideoxy-5-iodo-β-D-threo-pentofuranosyl)-thymine (7) A mixture of 6 (5.3 g, 15.05 mmol) and Ac2O (4.3 mL, 45.15 mmol) in pyridine (30 mL) was stirred at room temperature for 13 h. The reaction mixture was partitioned between CHCl3/saturated aqueous NaHCO3 (250 mL×3/50 mL). Silica gel column chromatography (hexane/EtOAc=1/1-1/2) of the organic layer gave 7 (5.53 g, 93%) as a foam: 1H NMR (CDCl3) δ 1.96 (3H, s, Me), 2.11 (3H, s, Ac), 2.11-2.16 (1H, m, H-2′a), 2.82 (1H, ddd, Jgem=15.8 Hz, J1′,2′b=8.0 Hz and J2′b,3′=5.7 Hz, H-2′b), 3.32-3.39 (2H, m, H-5′), 4.28 (1H, dt, J3′,4′=3.3 Hz and J4′,5′=7.1 Hz, H-4′), 5.48 (1H, dd, J2′b,3′=5.7 Hz and J3′,4′=3.3 Hz H-3′), 6.30 (1H, dd, J1′,2′a=2.8 Hz and J1′,2′b=8.0 Hz, H-1′), 7.38 (1H, d, J6,Me=0.7 Hz, H-6), 8.59 (1H, br, NH); FAB-MS m/z 395 (M++H).

Source