Facile synthesis of 3(2H)-furanones
J = 8.4 Hz, 2 Hz), 7.58 (d, 1H, J = 8 Hz), 1.68 (s, 6H)
ppm; 13C NMR (100 MHz, CDCl3): d = 175.5, 139.0,
135.9, 133.4, 131.2, 130.8, 128.4, 99.3, 79.2, 65.3,
d = 207.2, 183.4, 159.7, 130.3, 129.9, 119.9, 118.5, 111.8,
98.8, 89.1, 55.5, 23.1 ppm; HRMS (ESI): m/z calcd. for
C13H15O3 ([M?H]?) 219.1021, found 219.1046.
?
?
30.6 ppm; HRMS (ESI): m/z calcd. for C12H11Cl2O2
([M?H]?) 257.0136, found 257.0139.
5-(3,5-Dimethoxyphenyl)-2,2-dimethylfuran-3(2H)-one (1j,
C14H16O4) Yield 85%; white solid; m.p.: 103–105 °C; IR
-1
1H NMR
ꢀ
4-Hydroxy-1,4-diphenylpent-2-yn-1-one (2o, C17 H14O2) Yield
(KBr): m = 3007, 2981, 1683, 1602 cm
;
1
70%; white solid; m.p.: 98–100 °C; H NMR (400 MHz,
(400 MHz, CDCl3): d = 6.96 (d, 2H, J = 2 Hz),
6.62–6.67 (m, 1H), 5.93 (s, 1H), 3.86 (s, 3H), 1.50 (s, 6H)
ppm; 13C NMR (100 MHz, CDCl3): d = 207.0, 183.3,
160.9, 130.9, 105.0, 104.7, 99.0, 89.1, 55.6, 23.1 ppm;
CDCl3): d = 8.17-8.13 (m, 2H), 7.73–7.70 (m, 2H),
7.66–7.63 (m, 1H), 7.53–7.47 (m, 2H), 7.43–7.39 (m, 2H),
7.38–7.34 (m, 1H), 3.01 (bs, 1H), 1.95 (s, 3H) ppm; 13C
NMR (100 MHz, CDCl3): d = 177.7, 143.7, 136.4, 134.3,
129.6, 128.6, 128.6, 128.4, 128.2, 124.7, 96.4, 82.1,
32.5 ppm; MS (ESI): m/z = 251 ([M?H]?, 100%).
HRMS (ESI): m/z calcd. for C14H17O4 ([M?H]?)
?
249.1127, found 249.1117.
5-(3,4-Dichlorophenyl)-2,2-dimethylfuran-3(2H)-one
(1l,
4-Hydroxy-4-methyl-1-phenylhex-2-yn-1-one (2p, C13 H14-
O2) Yield 79%; gummy liquid; 1H NMR (400 MHz,
CDCl3): d = 8.09 (d, 2H, J = 7.2 Hz), 7.56 (t, 1H,
J = 7.2 Hz), 7.42 (t, 2H, J = 7.6 Hz), 3.96 (bs, 1H), 1.90-
1.82 (m, 2H), 1.62 (s, 3H), 1.10 (t, 3H, J = 7.6 Hz) ppm;
13C NMR (100 MHz, CDCl3): d = 178.1, 136.3, 134.2,
129.5, 98.1, 80.9, 68.7, 36.0, 28.4, 8.95 ppm; MS (ESI): m/
z = 203 ([M?H]?, 100%).
C12H10 Cl2O2) Yield 53%; white solid; m.p.: 128–130 °C;
1
IR (KBr): m = 3015, 2983, 1685, 1604 cm-1; H NMR
ꢀ
(400 MHz, CDCl3): d = 7.93 (d, 1H, J = 2 Hz),
7.62–7.69 (m, 1H), 7.58 (d, 1H, J = 8.4 Hz), 5.97 (s, 1H),
1.50 (s, 6H) ppm; 13C NMR (100 MHz, CDCl3):
d = 206.6, 180.7, 136.8, 133.5, 130.9, 129.0, 128.7, 126.3,
99.5, 89.5, 23.1 ppm; HRMS (ESI): m/z calcd. for C12H11
?
Cl2O2 ([M?H]?) 257.1036, found 257.1029.
4-Hydroxy-1-phenylpent-2-yn-1-one
(2q,
C11H10O2)
5-(2,4-Dichlorophenyl)-2,2-dimethylfuran-3(2H)-one (1m,
C12H10 Cl2O2) 2m was obtained as an impure product that
contaminated with other unidentified impurities starting
from 200 mg of 2,4-dichlorobenzoic acid. On treatment of
2m (impure) with aq. KOH following the general proce-
dure C, 1m was obtained in 52% yield (with respect to
acid) as white crystalline solid; m.p.: 133–135 °C; IR
[54] Yield 82%; gummy liquid; 1H NMR (400 MHz,
CDCl3): d = 8.08 (d, 2H, J = 8.4 Hz), 7.57 (t, 1H,
J = 7.2 Hz), 7.45 (t, 2H, J = 7.2 Hz), 5.74–5.67 (m, 1H),
2.53 (d, 1H, J = 2 Hz) ppm; 13C NMR (100 MHz,
CDCl3): d = 165.3, 133.1, 129.7, 129.4, 128.3, 82.1, 73.1,
60.5, 21.2 ppm; MS (ESI): m/z = 175 ([M?H]?, 100%).
(KBr): mꢀ = 3015, 2983, 1685, 1604 cm-1
;
1H NMR
5-(2-Iodophenyl)-2,2-dimethylfuran-3(2H)-one (1f, C12H11-
(400 MHz, CDCl3): d = 7.85 (d, 1H, J = 8.4 Hz), 7.55 (d,
1H, J = 2 Hz), 7.39 (dd, 1H, J = 8.4 Hz, 2 Hz), 6.35 (s,
1H), 1.49 (s, 6H) ppm; 13C NMR (100 MHz, CDCl3):
d = 207.5, 178.8, 138.2, 134.7, 131.0, 130.3, 127.5, 126.8,
104.4, 87.5, 23.0 ppm; HRMS (ESI): m/z calcd. for C12H11
IO2) Yield 53%; white solid; m.p.: 58–60 °C; IR (KBr):
m = 3015, 2981, 2210, 1735 cm-1; H NMR (400 MHz,
1
ꢀ
CDCl3): d = 7.86 (t, 2H, J = 4.2 Hz), 7.55 (dd, 2H,
J = 2 Hz, 7.2 Hz), 5.97 (s, 1H), 1.49 (s, 6H) ppm; 13C
NMR (100 MHz, CDCl3): d = 206.8, 182.4, 138.1, 128.5,
128.4, 99.7, 98.8, 89.2, 23.1 ppm; HRMS (ESI): m/z calcd.
?
Cl2O2 ([M?H]?) 257. 0136, found 257. 0161.
for C12H12IO2 ([M?H]?) 314.9882, found 314.9873.
2-Methyl-2,5-diphenylfuran-3(2H)-one (1o, C17H14O2) Yield
62%; gummy liquid; 1H NMR (400 MHz, CDCl3):
d = 7.98–7.94 (m, 2H), 7.63–7.54 (m, 5H), 7.41–7.32 (m,
3H), 6.03 (s, 1H), 1.88 (s, 3H) ppm; 13C NMR (100 MHz,
CDCl3): d = 204.3, 183.8, 138.3, 132.8, 128.9, 128.8,
128.5, 128.0, 127.1, 124.5, 98.6, 90.3, 24.4 ppm; MS
(ESI): m/z = 251 ([M?H]?, 100%).
?
5-(4-Iodophenyl)-2,2-dimethylfuran-3-one (1g, C12H11IO2) Yield
ꢀ
50%; white solid; m.p.: 150–152 °C; IR (KBr): m = 3014,
2982, 2224, 1680 cm-1 1H NMR (400 MHz, CDCl3):
;
d = 7.86 (dd, 2H, J = 6.8 Hz, 1.6 Hz), 7.55 (dd, 2H,
J = 6.4 Hz, 1.8 Hz), 5.98 (s, 1H), 1.5 (s, 6H) ppm; 13C
NMR (100 MHz, CDCl3): d = 206.8, 182.4, 138.1, 128.5,
128.4, 99.7, 98.8, 89.2, 23.1 ppm; HRMS (ESI): m/z calcd.
2-Ethyl-2-methyl-5-phenylfuran-3(2H)-one (1p, C13H14O2)
Yield 95%; gummy liquid; H NMR (400 MHz, CDCl3):
for C12H12IO2 ([M?H]?) 314.9882, found 314.9875.
?
1
d = 7.85–7.81 (m, 2H), 7.56–7.52 (m, 1H), 7.51–7.45 (m,
2H), 5.99 (s, 1H), 1.92–1.83 (m, 2H), 1.45 (s, 3H), 0.87 (t,
3H, J = 7.2 Hz) ppm; 13C NMR (100 MHz, CDCl3):
d = 206.8, 184.1, 132.5, 128.9, 128.8, 127.0, 99.9, 91.7,
30.0, 21.7, 7.48 ppm; MS (ESI): m/z = 203 ([M?H]?,
100%).
5-(3-Methoxyphenyl)-2,2-dimethylfuran-3(2H)-one (1i, C13-
H14O3) Yield 95%; white solid; m.p.: 86–88 °C; IR
-1
ꢀ
(KBr): m = 3015, 2980, 1685, 1597 cm
;
1H NMR
(400 MHz, CDCl3): d = 7.36-7.45 (m, 2H), 7.34 (t, 1H,
J = 1.6 Hz), 7.06-7.13 (m, 1H), 5.96 (s, 1H), 3.88 (s, 3H),
1.49 (s, 6H) ppm; 13C NMR (100 MHz, CDCl3):
123