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1
1.3. Cross-coupling of arylboronic acids with 3-bromo-2-
en-1-ones: general procedure
prisms, mp 868C; IR (nujol) lmax 1660 cm21; H NMR
(CDCl3) d 7.63 (4H, m, aryl), 7.54 (2H, d, J¼7.5 Hz, aryl),
7.27 (2H, d, J¼7.5 Hz, aryl), 6.49 (1H, t, J¼1.0 Hz,
vinylic), 2.82 (2H, td, J¼7.0, 1.2 Hz, CH2CH2CH2CO),
2.65 (2H, t, J¼8.1 Hz, CH2alkyl), 2.51 (2H, m, CH2CH2-
CH2CO), 2.18 (2H, m, CH2CH2CH2CO), 1.75–1.59 (2H,
m, alkyl), 1.41–1.24 (8H, m, alkyl), 0.82 (3H, t, J¼7.5 Hz,
CH3); 13C NMR (CDCl3) d 199.9 (s), 159.7 (s), 142.9 (s),
142.8 (s), 137.3 (s), 137.1 (s), 129.0 (d), 127.1 (d), 126.9 (d),
126.6 (d), 125.0 (t), 37.3 (t), 35.7 (t), 31.8 (t), 31.5 (t), 29.3
(t), 29.2 (t), 28.0 (t), 22.8 (t), 22.7 (t), 14.1 (q). Anal. calcd
for C25H30O: C, 86.66; H, 8.73%; found: C, 86.85; H,
8.48%.
A solution of the arylboronic acid (2.60 mmol) in ethanol
(15 mL) was added to a stirred mixture of the 3-bromo-2-en-
1-one (2.0 mmol) and tetrakis(triphenylphosphine)palla-
dium(0) (0.6 mg, 6.0 mmol) in benzene (30 mL) and
aqueous sodium carbonate (2 M, 30 mL) at 208C. The
stirred mixture was heated under reflux (approx. 958C) for
16 h. The product was extracted into diethyl ether
(2£50 mL) and the combined ethereal extracts were washed
with brine, dried (MgSO4) and evaporated. The residue was
purified by column chromatography or recrystallisation to
give the 3-arylated-2-cycloalken-1-one.
1.3.5. Cycloalkenone (3e). Chromatography using dichloro-
methane, followed by recrystallisation from light petroleum
afforded 3e (0.74 g, 92%), as prisms, mp 978C; IR (nujol)
1.3.1. Cycloalkenone (3a). Chromatography using 1:4 ethyl
acetate: light petroleum afforded 3a as a yellow oil (0.52 g,
97%) that solidified on standing, mp 248C; IR (nujol) lmax
1
lmax 1660 cm21; H NMR (CDCl3) d 7.52 (4H, m, aryl),
1
1665 cm21; H NMR (CDCl3) d 7.39 (2H, d, J¼8.0 Hz,
7.48 (2H, d, J¼7.5 Hz, aryl), 6.91 (2H, d, J¼7.5 Hz, aryl),
6.42 (1H, t, J¼1.0 Hz, vinylic), 3.90 (2H, t, J¼6.5 Hz,
OCH2), 2.75 (2H, td, J¼5.5, 1.0 Hz, CH2CH2CH2CO), 2.44
(2H, m, CH2CH2CH2CO), 2.22 (2H, m, CH2CH2CH2CO),
1.74 (2H, quintet, J¼6.5 Hz, OCH2CH2), 1.45–1.17 (14H,
m, alkyl), 0.82 (3H, t, J¼6.5 Hz, CH3); 13C NMR (CDCl3) d
199.9 (s), 159.2 (s), 142.8 (s), 142.5 (s), 136.7 (s), 132.2 (s),
128.1 (d), 126.8 (d), 126.6 (d), 124.9 (d), 118.3 (t), 114.9
(d), 68.1 (t), 37.3 (t), 31.9 (t), 29.6 (t), 29.4 (t), 29.3 (t), 29.3
(t), 28.0 (t), 26.1 (t), 22.8 (t), 22.7 (t), 14.1 (q). Anal. calcd
for C28H36O2: C, 83.12; H, 8.97%; found: C, 82.85; H,
8.77%.
aryl-2,6-H), 7.14 (2H, d, J¼8.0 Hz, aryl-3,5H), 6.35 (1H, m,
vinylic), 2.74 (2H, td, J¼7.0, 1.0 Hz, CH2CH2CH2CO),
2.55 (2H, t, J¼8.0 Hz, CH2aryl), 2.39 (2H, m, CH2CH2-
CH2CO), 2.05 (2H, m, CH2CH2CH2CO), 1.53 (2H, quintet,
J¼8.0 Hz, CH2CH2alkyl), 1.35–1.10 (8H, m, alkyl), 0.97
(3H, t, J¼8.0 Hz, CH3); 13C NMR (CDCl3) d 200.0 (s),
159.7 (s), 145.4 (s), 135.9 (s), 128.8 (d), 126.0 (d), 124.6 (d),
37.3 (t), 35.7 (t), 31.8 (t), 31.2 (t), 29.2 (t), 29.1 (t), 28.0 (t),
22.8 (t), 22.7 (t), 14.1 (q). LRMS (EI) m/e 270 (Mþ, 66%),
242 (49), 204 (40), 120 (43), 91 (45); HRMS calcd for
C19H26O 270.1984, found 270.1974.
1.3.2. Cycloalkenone (3b). Chromatography using 1:4 ethyl
acetate: light petroleum afforded 3b as a yellow oil (0.60 g,
96%); IR (nujol) lmax 1665 cm21; 1H NMR (CDCl3) d 7.38
(2H, d, J¼9.0 Hz, aryl-2,6H), 7.29 (2H, d, J¼9.0 Hz, aryl-
3,5H), 6.34 (1H, t, J¼1.5 Hz, vinylic), 2.68 (2H, td, J¼7.0,
1.5 Hz, CH2CH2CH2CO), 2.56 (2H, t, J¼8.0 Hz, CH2aryl),
2.48 (2H, m, CH2CH2CH2CO), 2.06 (2H, m, CH2CH2CH2-
CO), 1.56 (2H, quintet, J¼8.0 Hz, OCH2CH2aryl), 1.25–
1.15 (14H, m, alkyl), 0.93 (3H, t, J¼8.0 Hz, CH3); 13C
NMR (CDCl3) d 200.0 (s), 159.6 (s), 145.5 (s), 135.9 (s),
128.8 (d), 126.1 (d), 124.6 (d), 37.3 (t), 35.7 (t), 31.9 (t),
31.3 (t), 30.9 (t), 29.6 (t), 29.5 (t), 29.3 (t), 29.3 (t), 28.0 (t),
22.8 (t), 22.7 (t), 14.1 (q).
1.3.6. Cycloalkenone (3f). Recrystallisation from light
petroleum afforded 3f (0.67 g, 98%), as prisms, mp 638C; IR
1
(nujol) lmax 1665 cm21; H NMR (CDCl3) d 7.56 (2H, d,
J¼7.5 Hz, aryl), 6.92 (2H, d, J¼7.5 Hz, aryl), 6.38 (1H, t,
J¼1.0 Hz, vinylic), 3.98 (2H, t, J¼5.5 Hz, OCH2), 2.61
(2H, d, J¼1.0 Hz, vCCH2), 2.30 (2H, s, CH2CO), 1.76 (2H,
quintet, J¼5.5 Hz, OCH2CH2), 1.51–1.25 (12H, m, alkyl),
1.12 (6H, s, 2£ CH3), 0.91 (3H, t, J¼5.5 Hz, CH3); 13C
NMR (CDCl3) d 200.1 (s), 160.8 (s), 157.0 (s), 130.8 (s),
127.7 (d), 122.5 (d), 114.7 (d), 68.2 (t), 50.9 (t), 42.1 (t),
33.6 (t), 31.9 (t), 29.5 (t), 29.4 (t), 29.3 (t), 29.2 (t), 28.5 (q),
25.6 (t), 22.7 (t), 14.1 (q). Anal. calcd for C23H34O2: C,
80.65; H, 10.00%; found: C, 80.77; H, 9.77%.
1.3.3. Cycloalkenone (3c). Chromatography using dichlor-
omethane, followed by recrystallisation from light pet-
roleum afforded 3c (0.58 g, 92%), as prisms, mp 51–528C;
IR (nujol) lmax 1660 cm21; 1H NMR (CDCl3) d 7.44 (2H, d,
J¼8.0 Hz, aryl), 6.83 (2H, d, J¼8.0 Hz, aryl), 6.33 (1H, t,
J¼1.0 Hz, vinylic), 3.93 (2H, t, J¼6.0 Hz, OCH2), 2.67
(2H, td, J¼5.5, 1.0 Hz, CH2CH2CH2CO), 2.38 (2H, m,
CH2CH2CH2CO), 2.17 (2H, quintet, J¼6.0 Hz, CH2CH2-
alkyl), 1.72 (2H, m, CH2CH2CH2CO), 1.45–1.15 (12H, m,
alkyl), 0.82 (3H, t, J¼6.0 Hz, CH3); 13C NMR (CDCl3) d
199.9 (s), 160.9 (s), 159.2 (s), 130.5 (s), 127.6 (d), 123.6 (d),
114.6 (d), 68.2 (t), 37.2 (t), 31.9 (t), 29.5 (t), 29.4 (t), 29.3 (t),
29.2 (t), 27.8 (t), 26.0 (t), 22.8 (t), 22.7 (t), 14.1 (q). Anal.
calcd for C21H30O2: C, 80.21; H, 9.62%; found: C, 80.20; H,
9.82%.
1.3.7. Cycloalkenone (3g). Recrystallisation from light
petroleum afforded 3g (0.53 g, 97%), as prisms, mp 67–
698C; IR (nujol) lmax 1670 cm21; 1H NMR (CDCl3) d 7.50
(2H, d, J¼9.0 Hz, aryl), 6.83 (2H, d, J¼9.0 Hz, aryl), 6.35
(1H, t, J¼1.0 Hz, vinylic), 3.90 (2H, t, J¼6.0 Hz, OCH2),
2.87 (2H, m, CH2CH2CO), 2.42 (2H, m, CH2CH2CO), 1.71
(2H, quintet, J¼6.0 Hz, OCH2CH2), 1.45–1.10 (8H, m,
alkyl), 0.81 (3H, t, J¼6.0 Hz, CH3); 13C NMR (CDCl3) d
209.7 (s), 174.1 (s), 161.8 (s), 128.6 (s), 126.4 (d), 125.2 (d),
114.7 (d), 68.2 (t), 35.3 (t), 31.8 (t), 29.1 (t), 29.0 (t), 28.6 (t),
25.9 (t), 22.6 (t), 14.1 (q); LRMS (EI) m/e 272 (Mþ, 49%),
174 (100), 57 (18); HRMS calcd for C18H24O2 272.1769,
found 272.1776.
1.3.8. Cycloalkenone (3h). Recrystallisation from light
petroleum afforded 3h (0.55 g, 96%), as prisms, mp 44–
458C; IR (nujol) lmax 1700 cm21; 1H NMR (CDCl3) d 7.53
(2H, d, J¼9.0 Hz, aryl), 6.96 (2H, d, J¼9.0 Hz, aryl), 4.00
1.3.4. Cycloalkenone (3d). Recrystallisation from 1:5 ethyl
acetate: light petroleum afforded 3d (0.66 g, 95%), as