Pyridine → 11,12-Didehydro-5,6-dihydrodibenzo[a,e]cycloocten-5-yl 4-nitrophenyl carbonate

Participants

Reaction Steps

To a solution of 45 (0.22 g, 1 mmol) in CH2Cl2 (30 mL) was added 4-nitro-phenyl chloroformate (0.4 g, 2 mmol) and pyridine (0.4 ml, 5 mmol). After stirring 4 hours at ambient temperature, the reacting mixture was washed with brine (2×10 mL), and the organic layer was dried (MgSO4). The solvents were evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (hexane/ethyl acetate, 10/1, v/v) to afford 47 (0.34 g, 89%). 1H NMR (300 MHz, CDCl3): δ 8.23-8.18 (2H, aromatics), 7.56-7.54 (2H, aromatics), 7.46-7.18 (8H, aromatics), 5.52 (1H, dd, J=3.9, 15.3 Hz, CHOH), 3.26 (1H, dd, J=3.9, 15.3 Hz, CH2), 2.97 (1H, dd, J=3.9, 15.3 Hz, CH2). 13C NMR (75 MHz, CDCl3): δ 154.5, 150.7, 149.1, 148.7, 129.0, 127.4, 127.3, 126.7, 126.5, 125.5, 125.2, 124.3, 124.0, 122.6, 122.4, 120.8, 120.6, 120.2, 112.2, 108.5, 80.6, 44.8. MALDI HRMS: m/z 408.0852 [M+ Na+]. Calcd for C23H15NNaO5: 408.0848.

Provenance & Evidence