[CH3:1][C:2]1([NH:7][C:8](=[O:17])[O:9][CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH2:5][C:4](=C)[CH2:3]1.O.CC1C=CC=C(C)N=1.C(OI(C1C=CC=CC=1)OC(=O)C)(=[O:29])C>C1COCC1.O=[Os](=O)(=O)=O>[CH3:1][C:2]1([NH:7][C:8](=[O:17])[O:9][CH2:10][C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=2)[CH2:5][C:4](=[O:29])[CH2:3]1
Crude benzyl (1-methyl-3-methylidenecyclobutyl)carbamate (20.6 mmol) was dissolved in THF (10 mL), then water (0.100 mL), 2,6-dimethylpyridine (0.400 mL, 3.4 mmol), OsO4 (2.5% wt in 2-methyl-2-propanol, 0.340 mL, 0.027 mmol), and PhI(OAc)2 (1.0 g, 3.07 mmol) were added and the reaction mixture was stirred at rt for 3 hrs. The reaction was quenched with sat. sodium thiosulfate (20 mL) and extracted with EtOAc (two×30 mL). The combined organics were washed with sat. aqueous copper sulfate (three×50 mL), dried over MgSO4 and concentrated. The residue was purified via flash chromatography (eluting with 10%-20% EtOAc/heptanes) to give the title compound (558 mg, 12% yield) as a colorless oil. 1H NMR (400 MHz, chloroform-d) δ ppm 7.31-7.47 (m, 5H) 5.12 (s, 3H) 3.36-3.64 (m, 2H) 2.96-3.12 (m, 2H) 1.63 (s, 3H)); m/z (APCI+) for C13H15NO3 234.20 (M+H)+.
読み込み中…
