[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]([C:10]2[N:18]3[C:13]([CH:14]=[C:15]([OH:19])[CH:16]=[CH:17]3)=[C:12]([C:20](=[O:25])[C:21]([CH3:24])([CH3:23])[CH3:22])[C:11]=2[CH2:26][C:27]([CH3:34])([CH3:33])[C:28]([O:30][CH2:31][CH3:32])=[O:29])=[O:9])=[CH:4][CH:3]=1.[CH3:35][O:36][C:37]1[N:42]=[C:41]([CH2:43]O)[CH:40]=[CH:39][CH:38]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CC(OC(/N=N/C(OC(C)C)=O)=O)C>C1COCC1>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]([C:10]2[N:18]3[C:13]([CH:14]=[C:15]([O:19][CH2:43][C:41]4[CH:40]=[CH:39][CH:38]=[C:37]([O:36][CH3:35])[N:42]=4)[CH:16]=[CH:17]3)=[C:12]([C:20](=[O:25])[C:21]([CH3:23])([CH3:24])[CH3:22])[C:11]=2[CH2:26][C:27]([CH3:33])([CH3:34])[C:28]([O:30][CH2:31][CH3:32])=[O:29])=[O:9])=[CH:6][CH:7]=1To a cold (0° C.) solution of ethyl 3-{3-[(4-chlorophenyl)carbonyl]-1-(2,2-dimethylpropanoyl)-7-hydroxyindolizin-2-yl}-2,2-dimethylpropanoate (100 mg, 0.21 mmol), (6-methoxy-pyridin-2-yl)-methanol (35 mg, 0.25 mmol), and triphenylphosphine (65 mg, 0.25 mmol) in THF (5 mL) is added DIAD (48 μL, 0.25 mmol). The reaction is allowed to gradually warm to 23° C. and then stirred overnight. Silica gel is added and the mixture is concentrated in vacuo then purified by flash chromatography (SiO2, hexanes to 15% EtOAc in hexanes) to give ethyl 3-{3-[(4-chlorophenyl)carbonyl]-1-(2,2-dimethylpropanoyl)-7-[(6-methoxypyridin-2-yl)methoxy]indolizin-2-yl}-2,2-dimethylpropanoate (20 mg, 16%).
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