NMR (CDCl3, 200 MHz) d 0.91 (d, J = 6 Hz, 3H), 0.95–1.30 (m,
2H), 1.50–1.75 (m, 1H), 1.75–2.10 (m, 4H), 2.45–2.65 (m, 1H),
3.22–3.38 (m, 1H), 3.39 (s, 2H), 3.68 (s, 3H), 3.72 (s, 3H); 13C
NMR (CDCl3, 50 MHz) d 21.5, 31.6, 31.8, 32.3, 34.7, 35.9, 36.2,
51.5, 51.9, 117.4, 155.0, 168.9, 171.9; ESIMS (m/z) 263 [M+Na]+;
IR (CHCl3) nmax 1746, 1717, 1635 cm-1. Anal. Calcd for C13H20O4:
C, 64.98; H, 8.39. Found: C, 64.64; H, 8.70.
(d, J = 6 Hz, 3H), 1.43 (dt, J = 12 and 4 Hz, 1H), 1.52–1.72 (m,
1H), 1.75–1.90 (m, 1H), 2.18–2.55 (m, 3H), 2.61–2.75 (m, 1H),
3.31 (s, 2H), 3.70 (s, 3H), 4.90 (dd, J = 12 and 6 Hz, 1H); 13C
NMR (CDCl3, 50 MHz) d 17.1, 22.2, 27.1, 28.3, 31.6, 39.6, 52.2,
77.7, 116.7, 167.0, 170.0, 173.5; ESIMS (m/z) 247 [M+Na]+, 263
[M+K]+; IR (CHCl3) nmax 1754, 1737, 1691 cm-1. Anal. Calcd for
C12H16O4: C, 64.27; H, 7.19. Found: C, 64.13; H, 6.84.
Methyl 2-(2-oxo-2,4,5,6,7,7a-hexahydrobenzofuran-3-yl)acetate
(16a)
Methyl 2-(6-(tert-butyl)-2-oxo-2,4,5,6,7,7a-hexahydrobenzofuran-
3-yl)acetate (16e/e¢, diastereomeric mixture, 7 : 3)
It was obtained from alkylidenesuccinate 15a (2.26 g, 10.00 mmol)
It was obtained from alkylidenesuccinate 15e (2.82 g, 10.00 mmol)
and SeO2 (1.78 g, 16.00 mmol) using the same procedure described
above for 5a, as a white solid (1.76 g, 66%). Mp 70–73 ◦C; 1H NMR
(CDCl3, 200 MHz) d 0.87 (s, 9H), 0.90–2.35 (m, 5H), 2.45–2.87 (m,
2H), 3.25 (s, 0.60H), 3.27 (s, 1.40H), 3.67 (s, 3H), 4.67 (dd, J = 12
and 6 Hz, 0.30H), 4.97 (t, J = 8 Hz, 0.70H); 13C NMR (CDCl3, 50
MHz) d 22.2, 24.3, 25.9, 27.2, 27.4, 27.5, 28.2, 28.6, 30.6, 32.3, 32.8,
35.3, 43.0, 44.6, 52.0, 78.5, 80.9, 116.5, 117.9, 166.6, 167.2, 169.7,
169.9, 173.3, 173.8; ESIMS (m/z) 267 [M+H]+, 289 [M+Na]+, 305
[M+K]+; IR (CHCl3) nmax 1759, 1755, 1748, 1732, 1688 cm-1. Anal.
Calcd for C15H22O4: C, 67.65; H, 8.33. Found: C, 67.71; H, 8.60.
and SeO2 (1.78 g, 16.00 mmol) using the same procedure described
1
above for 5a, as a thick oil29 (1.55 g, 74%). H NMR (CDCl3,
200 MHz) d 1.20–1.62 (m, 3H), 1.84–2.10 (m, 2H), 2.21 (dt, J
= 14 and 6 Hz, 1H), 2.45–2.61 (m, 1H), 2.74–2.88 (m, 1H), 3.31
(s, 2H), 3.70 (s, 3H), 4.67 (dd, J = 10 and 6 Hz, 1H); 13C NMR
(CDCl3, 50 MHz) d 22.6, 26.2, 26.7, 28.4, 34.3, 52.3, 80.4, 117.0,
166.5, 170.0, 173.4; ESIMS (m/z) 211 [M+H]+, 233 [M+Na]+; IR
(CHCl3) nmax 1759, 1747, 1690 cm-1. Anal. Calcd for C11H14O4: C,
62.85; H, 6.71. Found: C, 62.47; H, 6.85.
Ethyl 2-(2-oxo-2,4,5,6,7,7a-hexahydrobenzofuran-3-yl)acetate
(16b)
Methyl 2-(2-oxo-4,5,6,7,8,8a-hexahydro-2H-cyclohepta[b]furan-3-
yl)acetate (16f)
It was obtained from alkylidenesuccinate 15b (2.54 g, 10.00 mmol)
and SeO2 (1.78 g, 16.00 mmol) using the same procedure described
above for 5a, as a thick oil (1.61 g, 72%). 1H NMR (CDCl3,
200 MHz) d 1.24 (dt, J = 8 and 2 Hz, 3H), 1.20–1.60 (m, 3H),
1.80–2.07 (m, 2H), 2.19 (dt, J = 14 and 6 Hz, 1H), 2.40–2.60 (m,
1H), 2.79 (dd, J = 14 and 2 Hz, 1H), 3.27 (s, 2H), 4.13 (dq, J = 8
and 2 Hz, 2H), 4.65 (dd, J = 12 and 6 Hz, 1H); 13C NMR (CDCl3,
50 MHz) d 14.0, 22.5, 26.1, 26.7, 28.5, 34.2, 61.1, 80.3, 117.0,
166.4, 169.5, 173.4; ESIMS (m/z) 225 [M+H]+, 247 [M+Na]+, 263
[M+K]+; IR (CHCl3) nmax 1752, 1734, 1687 cm-1. Anal. Calcd for
C12H16O4: C, 64.27; H, 7.19. Found: C, 64.38; H, 7.50.
It was obtained from alkylidenesuccinate 15f (2.40 g, 10.00 mmol)
and SeO2 (1.78 g, 16.00 mmol) using the same procedure described
above for 5a, as a thick oil (1.52 g, 68%). H NMR (CDCl3, 200
1
MHz) d 1.15–1.70 (m, 4H), 1.70–2.05 (m, 3H), 2.25–2.45 (m, 1H),
2.45–2.83 (m, 2H), 3.27 (s, 2H), 3.70 (s, 3H), 4.88–5.00 (m, 1H); 13
C
NMR (CDCl3, 50 MHz) d 25.4, 26.1, 27.6, 28.7, 29.7, 33.6, 52.2,
83.8, 119.9, 169.3, 169.7, 173.3; ESIMS (m/z) 225 [M+H]+, 247
[M+Na]+, 263 [M+K]+; IR (CHCl3) nmax 1756, 1747, 1669 cm-1.
Anal. Calcd for C12H16O4: C, 64.27; H, 7.19. Found: C, 64.07; H,
7.27.
Methyl 2-(2-oxo-2,4,5,6,7,7a-hexahydrobenzofuran-3-yl)-
Methyl 2-(2-oxo-2,3a,4,5-tetrahydronaptho[2,1-b]furan-1-yl)
propanoate (16c/c¢, diastereomeric mixture, 2 : 1)
acetate (16g)
It was obtained from alkylidenesuccinate 15c (2.40 g, 10.00 mmol)
It was obtained from alkylidenesuccinate 15g (2.74 g, 10.00 mmol)
and SeO2 (1.78 g, 16.00 mmol) using the same procedure described
above for 5a, as a thick oil (1.57 g, 70%). H NMR (CDCl3, 200
and SeO2 (1.78 g, 16.00 mmol) using the same procedure described
above for 5a, as a thick oil (1.96 g, 76%). H NMR (CDCl3, 200
1
1
MHz) d 1.10–1.60 (m, 3H), 1.40 (d, J = 8 Hz, 1H), 1.41 (d, J =
8 Hz, 2H), 1.83–2.25 (m, 3H), 2.45–2.60 (m, 1H), 2.80–2.95 (m,
1H), 3.60 (q, J = 6 Hz, 1H), 3.69 (s, 3H), 4.60 (dd, J = 10 and
6 Hz, 1H); 13C NMR (CDCl3, 50 MHz) d 15.7, 16.1, 22.5, 26.2,
26.3, 26.4, 26.5, 34.3, 34.4, 34.6, 34.8, 52.19, 52.24, 80.0, 122.8,
164.5, 172.9, 173.2; ESIMS (m/z) 225 [M+H]+, 247 [M+Na]+; IR
(CHCl3) nmax 1759, 1747, 1681 cm-1. Anal. Calcd for C12H16O4: C,
64.27; H, 7.19. Found: C, 64.17; H, 6.83.
MHz) d 1.70–1.95 (m, 1H), 2.62–2.76 (m, 1H), 3.06–3.17 (m, 2H),
3.53 (dd, J = 16 and 2 Hz, 1H), 3.73 (d, J = 16 Hz, 1H), 3.75
(s, 3H), 5.10 (dd, J = 14 and 6 Hz, 1H), 7.29–7.46 (m, 3H),
7.63 (dd, J = 6 and 2 Hz, 1H); 13C NMR (CDCl3, 50 MHz) d
27.6, 30.1 (2 carbons), 52.5, 79.0, 116.1, 127.1, 127.67, 127.73,
129.4, 131.1, 138.1, 159.5, 170.0, 173.9; ESIMS (m/z) 259 [M+H]+,
281 [M+Na]+; IR (CHCl3) nmax 1749, 1659 cm-1. Anal. Calcd for
C15H14O4: C, 69.76; H, 5.46. Found: C, 69.68; H, 5.72.
Methyl 2-(( )-6-methyl-2-oxo-2,4,5,6,7,7a-hexahydrobenzofuran-
Ethyl 2-(2-oxo-2,3a,4,5-tetrahydronaptho[2,1-b]furan-1-yl)acetate
3-yl)acetate (16d/d¢, diastereomeric mixture, 3 : 1)
(16h)
It was obtained from alkylidenesuccinate 15d (2.40 g, 10.00 mmol)
and SeO2 (1.78 g, 16.00 mmol) using the same procedure described
above for 5a, as a white solid (1.61 g, 72%). Recrystalization of
16d/d¢ with petroleum ether provided analytically pure 16d as a
It was obtained from alkylidenesuccinate 15h (3.02 g, 10.00 mmol)
and SeO2 (1.78 g, 16.00 mmol) using the same procedure described
1
above for 5a, as a thick oil (1.99 g, 73%). H NMR (CDCl3, 200
MHz) d 1.25 (t, J = 8 Hz, 3H), 1.70–1.95 (m, 1H), 2.60–2.75 (m,
1H), 3.05–3.20 (m, 2H), 3.52 (dd, J = 16 and 2 Hz, 1H), 3.70 (d, J
◦
1
white solid. Mp 86–88 C; H NMR (CDCl3, 200 MHz) d 1.15
This journal is
The Royal Society of Chemistry 2011
Org. Biomol. Chem., 2011, 9, 6312–6322 | 6319
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