反应详情

5-Methyl-3-phenyl-(S)-1H-inden-1-ol (750 mg, 3.41 mmol) and DABCO (190 mg, 1.71 mmol) were dissolved in dry THF:triethylamine 20:1 (15 ml) and refluxed for 3 h. The reaction mixture was evaporated to dryness. Flash chromatography eluting with ethyl acetate:pentane 5:95 gave 690 mg (92%) of the title compound. Rf 0.62 (ethyl actetate:pentane 20:80) (ChiralCel OD-H) 0.5 ml/min of hexane/isopropanol: 95/5 (S)-isomer 19.12 min, (R)-isomer 22.33 min, 89% ee. IR (neat cm−1): 3027, 2361, 1710, 1605, 1280, 1238, 1040. 1H NMR δ: 2.39 (s, 3H), 2.69 (dd, J=3.0, 19.2 Hz, 1H), 3.23 (dd, J=8.0, 19.2 Hz, 1H), 4.53 (q, J=4 Hz, 1H), 7.07 (s, 1H), 7.14 (d, J=8.4 Hz, 1H), 7.15 (s, 1H), 7.26 (m, 2H), 7.33 (m, 2H), 7.72 (d, J=7.6 Hz, 1H). 13C NMR δ: 22.1, 44.3, 46.9, 123.2, 126.9, 127.0, 127.6, 128.9, 134.5, 143.8, 146.3, 158.4, 205.5. MS (EI 70 eV) m/z (rel. intensity): 220 (100) [M+], 207 (55), 194 (19), 178 (60), 144 (10).

1. temperaturerefluxed for 3 h
2. customThe reaction mixture was evaporated to dryness
3. washFlash chromatography eluting with ethyl acetate:pentane 5:95