R. Alvarez, A. R. de Lera / Tetrahedron: Asymmetry 9 (1998) 3065–3072
3071
90:10 CH2Cl2:MeOH) furnished boronic acid 10 in 45% yield. [α]D −1.3 (c 0.23, CH3OH). 1H NMR
(300.13 MHz, CD2Cl2): δ 1.14 (3H, d, J=6.3 Hz, 3H5), 2.4–2.2 (2H, m, 2H3), 3.80 (1H, app. q, J=6.3 Hz,
H4), 5.63 (1H, d, J=17.7 Hz, H1), 6.53 (1H, dt, J=17.7, 7.0 Hz, H2). 13C NMR (75.89 MHz, CD2Cl2): δ
16.8 (q), 47.1 (t) 67.9 (d), 150.4 (d), 156.3 (d). IR (NaCl): ν 3675–3100 (br, O–H), 2968 (s, C–H), 2929
25
(m, C–H), 1637 (m), 1345 (s, B–O) cm−1
.
3.7. 2(S)-(+)-(4E,6E,11E)-12-(3-Pyridyl)-dodeca-4,6,11-triene-2-ol (haminol A, 1a)
Iodide 9 (0.073 g, 0.245 mmol) in THF (2 mL) was added to a suspension of Pd(PPh3)4 (0.028 g,
0.0024 mmol) in anhydrous THF (3 mL). After stirring for 30 min, a solution of boronic acid 10 (0.071
g, 0.269 mmol) in THF (5 mL) and 10% aqueous TlOH (1.68 mL, 0.76 mmol) were added sequentially.
After stirring at room temperature for 2 h, the reaction mixture was diluted with Et2O (10 mL) and
filtered through Celite. The filtrates were washed with saturated aqueous NaHCO3 (3×10 mL) and the
aqueous layer was extracted with ethyl acetate (3×10 mL). The organic layers were dried over MgSO4
and concentrated. Chromatography (SiO2, gradient from hexane to ethyl acetate) afforded 0.040 g (72%)
25
25
of compound 1a as a yellow oil.3,11 [α]D +4.5 (c 0.17, CH3OH); lit.3 [α]D +5.0 (c 0.3, CH3OH). 1H
NMR (400.13 MHz, CDCl3): δ 1.22 (3H, d, J=6.2 Hz, 3H1), 1.60 (2H, quintet, J=7.4 Hz, 2H9), 2.1–2.2
(3H, m, H3+2H8), 2.2–2.3 (3H, m, H3+2H10), 3.84 (1H, app. sextet, J=6.2 Hz, H2), 5.57 (1H, dt, J=14.4,
7.1 Hz, H4), 5.66 (1H, dt, J=14.4, 7.1 Hz, H7), 6.05 (1H, dd, J=14.4, 10.4 Hz, H5), 6.12 (1H, dt, J=14.4,
0
10.4 Hz, H6), 6.29 (1H, dt, J=15.9, 6.3 Hz, H11), 6.37 (1H, d, J=15.9 Hz, H12), 7.2–7.3 (1H, m, H5 ),
0
0
0
7.66 (1H, d, J=7.9 Hz, H4 ), 8.44 (1H, br, H6 ), 8.57 (1H, br, H2 ). IR (NaCl): ν 3600–3100 (br, O–H),
2963 (m, C–H), 2926 (m, C–H) cm−1
.
3.8. 2(S)-(−)-(4E,6E,11E)-2-Acetoxy-12-(3-pyridyl)-dodeca-4,6,11-triene (haminol B, 1b)
Ac2O (0.03 mL, 0.56 mmol) was added to a solution of alcohol 1a (0.017 g, 0.066 mmol) in pyridine
(0.06 mL) and the mixture was reacted at room temperature for 4 h. After evaporation of solvents, the
residue was dissolved in CHCl3 (5 mL), washed with H2O (3×2 mL), aqueous saturated NaHCO3 (2
mL) and brine (2 mL), and concentrated. Chromatography (silica gel, ethyl acetate) afforded acetate 1b
in 65% yield.3,11 [α]D −23.1 (c 0.024, CH3OH); lit.3 [α]D −24.0 (c 0.4, CH3OH). 1H NMR (400.13
MHz, CD2Cl2): δ 1.23 (3H, d, J=6.3 Hz, 3H1), 1.61 (2H, quintet, J=7.5 Hz, 2H9), 2.01 (3H, s, COCH3),
2.2–2.1 (3H, m, H3+2H8), 2.4–2.3 (3H, m, H3+2H10), 4.90 (1H, app. sextet, J=6.3 Hz, H2), 5.54 (1H, dt,
J=14.1, 7.1 Hz, H4), 5.65 (1H, dt, J=14.1, 7.1 Hz, H7), 6.0–6.1 (2H, m, H5+H6), 6.3–6.4 (1H, m, H11),
25
25
0
0
6.40 (1H, d, J=16.1 Hz, H12), 7.23 (1H, dd, J=7.8, 4.8 Hz, H5 ), 7.68 (1H, d, J=7.8 Hz, H4 ), 8.42 (1H,
0
0
br, H6 ), 8.56 (1H, br, H2 ). IR (NaCl): ν 2928 (m, C–H), 2856 (m, C–H), 1740 (s, C_O), 1259 (s), 1252
(s), 1027 (s), 799 (s) cm−1. MS m/z (%): 299 (M+, 4), 278 (41), 277 (76), 240 (27), 239 (100), 201 (23),
183 (10), 171 (19), 158 (18), 145 (11), 144 (13), 133 (16), 132 (63), 130 (33), 119 (19), 118 (29). HRMS:
calcd for C19H25NO2, 299.1885; found, 299.1886.
Acknowledgements
We thank FIS (Contract 95/1534), Xunta de Galicia (Grant XUGA30106B97) and Universidade de
Vigo (matching Grant 95/1534, fellowship to Dr. Alvarez) for financial support, and Ms. María Herrero
for preliminary experiments in this area