反应详情

Under nitrogen, 2,4-dibromo-5-hydroxyphenyl acetate (4.00 grams, 12.9 millimoles, 1.0 equivalent) and cyclohexyl vinyl ether (2.74 milliliters, 19.3 millimoles, 1.5 equivalents) was dissolved in toluene (50 milliliters). Trifluoroacetic acid (0.10 milliliters, 1.29 millimoles, 0.10 equivalent) was added, and the mixture stirred at room temperature overnight (18-24 hours). The reaction was quenched by adding triethylamine (0.53 milliliters, 3.87 millimoles, 0.3 equivalent), and the volatiles were removed on the rotary evaporator. The resulting oil was taken up in diethyl ether (30 milliliters) and filtered through a plug of basic alumina. The product was rinsed through with additional ether (500 milliliters). The solvent was removed on the rotary evaporator and the resulting oil was pumped on for over 24 hours. The product was obtained as a racemate in the form of a slightly yellow oil (3.77 grams, 8.64 millimoles, 67%). 1H NMR (400 MHz, CDCl3) δ 7.76 (s, 1H), 7.00 (s, 1H), 5.48 (q, J=5.4 Hz, 1H), 3.69 (tt, J=9.1, 3.9 Hz, 1H), 2.34 (s, 3H), 1.94-1.63 (m, 4H), 1.55-1.48 (m, 1H), 1.52 (d, J=5.3 Hz, 3H), 1.44-1.02 (m, 5H); 13C NMR (101 MHz, THF-d8) δ 168.19, 154.65, 149.40, 136.68, 114.35, 111.79, 108.79, 100.94, 75.66, 34.45, 33.33, 26.69, 24.97, 24.85, 20.94, 20.55; FTIR (film) 647, 703, 725, 840, 891, 979, 1018, 1059, 1170, 1190, 1248, 1279, 1368, 1393, 1466, 1584, 1779, 2856, 2932 cm−1; UV/Vis 223, 232 (overlapping), 290 nm; ESI/MS/MS of m/z=459: 459 [M79Br/81Br+Na]+, 341, 281, 207, 151, 109 83 [C6H11]+; HRMS (ESI+): calc. for C16H20Br2NaO4+[M+Na]+456.9621, found 456.9628.

1. customThe reaction was quenched
2. customthe volatiles were removed on the rotary evaporator
3. filtrationfiltered through a plug of basic alumina
4. washThe product was rinsed through with additional ether (500 milliliters)
5. customThe solvent was removed on the rotary evaporator
6. customwas pumped on for over 24 hours