Synthesis of 2,3-Dihydroxy-1-Epilupinine
201
reaction was monitored by TLC. Subsequently, the solvent was evaporated and
the products were separated by chromatography using hexane/AcOEt 1:1 v/v
as an eluent to afford 13 (31 mg, 47%) and 14 (21 mg, 32%).
13: m.p. 109.5–110.58C; [a]D mixture of invertomers þ120.2 (c 1.2, CH2Cl2); IR
(film CHCl3): v 1745 cm21; 1H NMR (500 MHz, CDCl3) taken for the mixture of
invertomers d: major component 13a, 5.23 (dd, 1H, J ¼ 3.7, 9.5 Hz, H-2), 4.94
(ddd, 1H, J ¼ 2.2, 3.9, 9.5 Hz, H-3), 4.54 (dd, 1H, J ¼ 3.7, 8.5 Hz, H-1a), 4.37
(dd, 1H, J ¼ 3.9, 12.6 Hz, CHHOAc), 4.27 (dd, 1H, J ¼ 2.2, 12.6 Hz,
CHHOAc), 3.52 (m, 1H, H-9), 3.26 (dd, 1H, J ¼ 8.5, 10.0 Hz, H-5a), 2.54
(m, 1H, H-90), 2.32 (ddd, 1H, J ¼ 2.3, 10.0, 11.2 Hz, H-5b), 2.22 (m, 1H, H-6),
2.14, 2.08 (2s, 6H, 2 ꢀ OAc), 1.85 (m, 1H, H-8), 1.66 (m, 1H, H-80), 1.56–1.45
(m, 2H, H-60,7), 1.23 (m, 1H, H-70); minor component 13b, 5.16 (dd,
1H, J ¼ 3.2, 9.8 Hz, H-2), 5.01 (ddd, 1H, J ¼ 2.1, 3.0, 9.8 Hz, H-3), 4.84 (dd,
1H, J ¼ 3.2, 8.4 Hz, H-1a), 4.38 (dd, 1H, J ¼ 3.0, 12.6 Hz, CHHOAc), 4.28
(dd, 1H, J ¼ 2.1, 12.6 Hz, CHHOAc), 3.66 (m, 1H, H-5b), 3.42 (dd, 1H,
J ¼ 6.8, 8.4 Hz, H-5a), 3.10 (m, 1H, H-9), 2.84 (m, 1H, H-90), 2.14, 2.08 (2s,
6H, 2 ꢀ OAc), 1.94–1.73 (m, 4H, H-6,7,70,8), 1.58–1.42 (m, 2H, H-60,80);
1H NMR (500 MHz, toluene-d8 1008C) d: 5.02 (dd, 1H, J ¼ 3.7, 9.3 Hz, H-2),
4.70 (ddd, 1H, J ¼ 2.7, 4.3, 9.3 Hz, H-3), 4.36 (dd, 1H, J ¼ 3.7, 8.3 Hz, H-1a),
4.21 (dd, 1H, J ¼ 4.3, 12.4 Hz, CHHOAc), 4.04 (dd, 1H, J ¼ 2.7, 12.4 Hz,
CHHOAc), 3.04 (m, 1H, H-9), 2.80 (t, 1H, 8.3 Hz, H-5a), 2.46 (m, 1H, H-90),
1.78 (m, 1H, H-5b), 1.72 (2s, 6H, 2 ꢀ OAc), 1.48–1.24 (m, 5H, H-6, 60, 7, 8,
80), 0.97 (m, 1H, H-70); 13C NMR (125 MHz, CDCl3) taken for the mixture of
invertomers d: major component, 170.4, 169.4, 167.6, 73.0, 71.2, 71.1, 66.2,
61.4, 55.1, 52.3, 28.9, 24.4, 23.2, 20.7, 20.6; minor component, 170.4, 169.7,
168.5, 72.8, 71.4, 66.8, 66.1, 61.4, 50.3, 50.2, 24.5, 22.0, 20.8, 20.6, 19.6;
MSHR (ESI) m/z [M þ H]þ, calcd. for C15H22NO7: 328.13908. Found:
328.13965.
14: [a]D mixture of invertomers þ33.5 (c 0.5, CH2Cl2); IR (film, CHCl3): v
1
1746 cm21; H NMR (500 MHz, CDCl3) taken for the mixture of invertomers
d: major component, 5.19 (dd, 1H, J ¼ 7.7, 9.0 Hz, H-2), 4.48 (ddd, 1H, J ¼ 2.0,
5.0, 9.0 Hz, H-3), 4.42 (dd, 1H, J ¼ 5.0, 12.4 Hz, CHHOAc), 4.35 (dd, 1H,
J ¼ 7.7, 9.7 Hz, H-1a), 4.22 (dd, 1H, J ¼ 2.0, 12.4 Hz, CHHOAc), 3.46
(m, 1H, H-9), 3.25 (dd, 1H, J ¼ 9.7, 9.8 Hz, H-5a), 2.56 (m, 1H, H-90), 2.46
(ddd, 1H, J ¼ 2.0, 9.8, 10.9 Hz, H-5b), 2.38 (m, 1H, H-6), 2.12, 2.08 (2s, 6H,
2 ꢀ OAc), 1.86–1.74 (m, 2H, H-7,8), 1.64 (m, 1H, H-80), 1.51 (m, 1H, H-60),
1.30 (m, 1H, H-70); minor component, 5.21 (m, 1H, H-2), 4.59 (m, 1H, H-3),
4.48 (m, 1H, H-1a), 4.42 (m, 1H, CHHOAc), 4.25 (m, 1H, CHHOAc), 3.75
(m, 1H, H-5b), 3.35 (m, 1H, H-5a), 3.10 (m, 1H, H-9), 2.95 (m, 1H, H-90),
2.12, 2.08 (2s, 6H, 2 ꢀ OAc), 2.00–1.20 (m, 6H, H-6,60,7,70,8,80); 1H NMR
(500 MHz, toluene-d8 1008C) d: 5.16 (dd, 1H, J ¼ 7.5, 9.1 Hz, H-2), 4.30