Acetic Anhydride → 1-[5-O-Acetyl-2-deoxy-3-O-(t-butyldimethylsilyl)-4-ethynyl-beta-D-threo-pentofuranosyl]thymine
Reaction equation
[Si:1]([O:8][C@H:9]1[C@@:13]([C:16]#[CH:17])([CH2:14][OH:15])[O:12][C@@H:11]([N:18]2[CH:26]=[C:24]([CH3:25])[C:22](=[O:23])[NH:21][C:19]2=[O:20])[CH2:10]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2].[CH3:27][C:28](OC(C)=O)=[O:29]>N1C=CC=CC=1>[C:28]([O:15][CH2:14][C@@:13]1([C:16]#[CH:17])[O:12][C@@H:11]([N:18]2[CH:26]=[C:24]([CH3:25])[C:22](=[O:23])[NH:21][C:19]2=[O:20])[CH2:10][C@H:9]1[O:8][Si:1]([C:4]([CH3:7])([CH3:5])[CH3:6])([CH3:2])[CH3:3])(=[O:29])[CH3:27]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a pyridine (4 mL) solution of 10a (161 mg, 0.423 mmol) was added Ac2O (120 mL, 1.269 mmol) at 0° C., and the mixture was stirred at room temperature for 11 h. The reaction mixture was partitioned between CHCl3/saturated aqueous NaHCO3 (60 mL×3/20 mL). Silica gel column chromatography (hexane/EtOAc=3/1) of the organic layer gave 11 (169.7 mg, 95%) as a foam: UV (MeOH): λmax 266 nm (ε9200), λmin 234 nm (ε2000); 1H NMR (CDCl3) δ0.10 and 0.14 (6H, each as s, SiMe), 0.90 (9H, s, SiBu-t), 1.90-1.94 (4H, m, H-2′a and Me), 2.14 (3H, s, Ac), 2.58 (1H, s, ethynyl), 3.01 (1H, ddd, Jgem=14.8 Hz, J1′,2′b=8.3 Hz and J2′b,3′=5.0 Hz, H-2′b), 4.37 (1H, d, Jgem=11.1 Hz, H-5′a), 4.45 (1H, d, J2′b,3′=5.0 Hz, H-3′), 4.53 (1H, d, Jgem=11.1 Hz, H-5′b), 6.40 (1H, dd, J1′,2′a=2.8 Hz and J1′,2′b=8.3 Hz, H-1′), 7.53 (1H, d, J6,Me=1.3 Hz, H-6), 8.04 (1H, br, NH); FAB-MS m/z 461 (M++K). Anal. Calcd for C20H30N2O6Si: C, 56.85; H, 7.16; N, 6.63. Found: C, 56.84; H, 7.35; N, 6.26.
Workup
- customThe reaction mixture was partitioned between CHCl3/saturated aqueous NaHCO3 (60 mL×3/20 mL)
Sources & evidence
- ORD record
- ord-35740aa516b941dc94a68e284b478a36
- Source dataset
- uspto-grants-2012_06
- Patent number
- US08193165B2
Reaction notes
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