1386
G. Fontana et al. / Tetrahedron: Asymmetry 9 (1998) 1381–1387
3.4. General procedure for the preparation of benzoyl derivatives
To a solution of alcohol (0.2 mmol) in 0.6 mL of dry CH2Cl2 and 0.6 mL of dry pyridine, was added
50 µL of freshly distilled benzoyl chloride and the reaction mixture was refluxed until completion. After
the usual workup the crude product was purified by flash chromatography using the same eluent as for
TLC.
3.5. (S)-1,2,3,4-Tetrahydrophenanthren-2-ol 4a
25
1
TLC Rf 0.29 (eluent A); [α]D −51.0 (c 0.42, 72% e.e.) (cf. Koreeda et al.7); H NMR (300 MHz)
δ 1.91–2.06 (m, 2H, H-3a and OH), 2.17–2.34 (m, 1H, H-3b), 2.92 (dd, 1H, J=15.6 and 7.8 Hz, H-1a),
3.12 (app dd, 1H, J=17.1, 6.8 Hz, H-4a), 3.21 (dd, 1H, J=15.6, 4.9 Hz, H-1b), 3.35 (app dt, 1H, J=17.1,
5.9 Hz, H-4b), 4.18–4.26 (m, 1H, H-2), 7.18 (d, 1H, J=8.5 Hz, H-10), 7.42–7.53 (m, 2H, H-6 and H-7),
7.64 (d, 1H, J=8.5 Hz, H-9), 7.79 (d, 1H, J=6.8 Hz, H-8), 7.95 (d, 1H, J=8.8 Hz, H-5); 13C NMR (50
MHz) δ 23.68 (t), 31.24 (t), 39.17 (t), 66.89 (d), 122.90 (d), 124.94 (d), 125.98 (d), 126.32 (d), 128.10
(d), 128.35 (d), 130.25 (s), 131.24 (s), 132.00 (s), 132.26 (s); UV λmax (log ε) 288 (3.57), 278 (3.56), 244
(3.65), 324 (2.62); 4a (S)-MTPA ester 4b, TLC Rf 0.48 (eluent B); 19F NMR δ −71.99 (14%), −71.78
(86%).
3.6. (S)-1,2,3,4-Tetrahydrophenanthren-2-ol benzoate 4c
25
TLC Rf 0.52 (eluent A); UV λmax (log ε) 228 (4.94), 280 (3.85); [α]D −74.8 (c 0.72, 72% e.e.);
CD λmax (∆ε) 219 (+13.6), 229 (−25.2) (cf. Koreeda et al.7); 1H NMR (200 MHz) δ 2.24–2.37 (m, 2H,
H-3), 3.14–3.49 (m, 4H, H-1 and H-4), 5.54–5.65 (m, 1H, H-2), 7.21 (d, 1H, J=8.5 Hz), 7.38–7.56 (m,
6H) 7.67 (d, 1H, J=8.5 Hz), 7.83 (d, 1H, J=7.5 Hz) and 8.01 (app t, 2H, J=8.1 Hz) (aromatic H); 13C
NMR (75 MHz) δ 23.16 (t), 27.63 (t), 35.39 (t), 70.01 (d), 122.93 (d), 125.07 (d), 126.10 (d), 126.45 (d),
127.95 (d), 128.29 (d), 128.47 (d), 129.57 (d), 130.23 (s), 130.56 (s), 130.72 (s), 132.10 (s), 132.35 (s),
132.80 (d), 166.20 (s).
3.7. (R)-1,2,3,4-Tetrahydrophenanthren-3-ol 6a
25
1
TLC Rf 0.25 (eluent B); [α]D +13.8 (c 0.40, 30% e.e.) [lit.6 −49, for optically pure (S)-6a]; H
NMR (300 MHz) δ 1.83–1.97 (m, 2H, H-2a and OH), 2.11–2.16 (m, 1H, H-2b), 2.93–3.14 (m, 3H, H2-1
and H-4a), 3.51 (dd, 1H, J=16.7, 2.0 Hz, H-4b), 4.26–4.34 (m, 1H, H-3), 7.21 (d, 1H, J=8.4 Hz, H-10),
7.42–7.53 (m, H-6 and H-7), 7.63 (d, 1H, J=8.4 Hz, H-9), 7.79 (d, 1H, J=9.1 Hz, H-8), 7.93 (d, 1H,
J=8.3 Hz, H-5); 13C NMR (75 MHz) δ 28.02 (t), 31.32 (t), 35.02 (t), 67.67 (d), 122.73 (d), 125.00 (d),
126.12 (d), 126.29 (d), 127.48 (d), 128.49 (d), 128.5 (s), 132.28 (s), 132.31 (s), 133.03 (s); UV λmax
(log ε) 244 (3.63), 282 (3.69), 276 (3.66); 6a (S)-MTPA ester 6b, TLC Rf 0.70 (eluent B); 19F NMR δ
−71.32 (65%), −71.14 (35%).
3.8. (R)-1,2,3,4-Tetrahydrophenanthren-3-ol benzoate 6c
25
TLC Rf 0.67 (eluent A); UV λmax (log ε) 228 (5.00), 280 (3.93); [α]D −8.54 (c 0.57, 30% e.e.);
CD λmax (∆ε) 222 (+21), 229 (−30) (cf. Boyd et al.6); 1H NMR (200 MHz) δ 2.17–2.33 (m, 2H, H2-2),
3.00–3.41 (m, 3H, H2-1 and H-4a), 3.65 (dd, 1H, J=17.1, 5.3 Hz, H-4b), 5.68 (app quint., 1H, J=5.7
Hz, H-3), 7.27 (d, 1H, J=8.4 Hz, H-10), 7.40–7.61 (m, 4H, H-6, H-7, H-20, H-30, H-50 and H-60), 7.69