2404
A. Patin, P. Belmont
PAPER
Pauson–Khand Reaction; Typical Procedure
MS: m/z (%) = 328 (100) [MH+], 310 (8) [MH+ – H2O].
5-Hydroxy-1-trimethylsilyl-3,3a,4,5-tetrahydro-2H-cyclopen-
ta[c]acridin-2-one (3a)
HRMS: m/z [MH+] calcd for C22H17NO2: 328.1337; found:
328.1330.
Co2(CO)8 (450 mg, 1.32 mmol) was added to a solution of enyne
(295 mg, 1.0 mmol) in CH2Cl2 (30 mL) at r.t. under Ar. After the
mixture was stirred for 2 h, NMO (1.17 g, 10.0 mmol) was added
and the mixture was further stirred overnight. After filtration
through a short pad of silica and elution with EtOAc, the filtrate was
concentrated to dryness. Chromatography of the residue with a mix-
ture of cyclohexane–EtOAc (3:1) afforded cyclopentenone (225
mg, 70%) as a yellow solid with some starting material (69 mg,
23%); mp 182 °C.
5-Hydroxy-1-tetrahydro-2H-2-pyranyloxymethyl-3,3a,4,5-tet-
rahydro-2H-cyclopenta[c]acridin-2-one (3d)
Yield: (75%); mp 70–71 °C.
IR (neat): 3363, 2920, 2361, 1681, 1228, 1020, 917 cm–1.
1H NMR (300 MHz, CDCl3): d = 1.30–1.85 (m, 6 H), 2.06 (dt, J =
3.0, 18.6 Hz, 1 H), 2.28–2.44 (m, 3 H), 2.60–2.75 (m, 1 H), 3.38–
3.95 (m, 3 H), 4.63 (d, J = 10.5 Hz, 1 H), 4.76–5.08 (m, 2 H), 5.30
(d, J = 10.5 Hz, 1 H), 7.42–7.52 (m, 1 H), 7.60–7.73 (m, 2 H), 7.78–
8.12 (m, 2 H).
13C NMR (75 MHz, CDCl3): d = 10.0 (CH), 19.0 (CH2), 19.1 (CH2),
30.3 (CH2), 30.4 (CH2), 32.7 (CH), 33.2 (CH), 37.2 (CH2), 37.3
(CH2), 37.4 (CH2), 40.6 (CH2), 40.9 (CH2), 58.1 (CH2), 58.4 (CH2),
61.8 (CH2), 67.1 (CH), 67.2 (CH), 98.9 (CH), 99.4 (CH), 127.4 (2
× CH), 127.7 (CH), 127.9 (2 × C), 129.7 (CH), 129.8 (2 × CH),
129.9 (CH), 130.0 (CH), 132.6 (C), 132.9 (C), 137.2 (CH), 137.4
(CH), 137.9 (C), 138.2 (C), 139.0 (C), 147.7 (C), 149.5 (2 × C),
150.7 (C), 162.6 (C), 166.7 (2 × C), 207.8 (C), 207.9 (C), 209.2 (C).
IR (neat): 3244, 3073, 2957, 2899, 2162, 1248, 1060, 857 cm–1.
1H NMR (300 MHz, CDCl3): d = 0.32 [s, 9 H, Si(CH3)3], 1.90 (dt,
J = 3.3, 13.5 Hz, 1 H), 2.22 (dd, J = 4.2, 18.0 Hz, 1 H), 2.48 (ddd,
J = 2.4, 4.2, 14.7 Hz, 1 H), 2.78 (dd, J = 6.9, 18.0 Hz, 1 H), 2.87 (br
s, 1 H), 3.64 (ddt, J = 1.8, 6.3, 12.9 Hz, 1 H), 5.15 (t, J = 2.7 Hz, 1
H), 7.56 (ddd, J = 1.2, 6.6, 7.8 Hz, 1 H), 7.74 (ddd, J = 1.5, 6.9, 8.1
Hz, 1 H), 7.82 (d, J = 8.1 Hz, 1 H), 8.09 (d, J = 8.0 Hz, 1 H), 8.20
(s, 1 H).
13C NMR (75 MHz, CDCl3): d = 0.7 (3 × CH3), 35.2 (CH), 37.7
(CH2), 43.5 (CH2), 67.3 (CH), 127.7 (CH), 127.8 (CH), 128.2 (C),
129.3 (CH), 130.3 (CH), 132.6 (C), 137.3 (CH), 142.3 (C), 147.4
(C), 149.7 (C), 179.9 (C), 212.1 (C).
MS: m/z (%) = 366 (71) [MH+], 282 (100) [MH+ – THP], 264 (9)
[MH+ – THP – H2O].
HRMS: m/z [MH+] calcd for C22H23NO4: 366.1705; found:
366.1710.
MS: m/z (%) = 324 (68) [MH+], 306 (100) [MH+ – H2O].
HRMS: m/z [MH+] calcd for C19H21NO2Si: 324.1420; found:
324.1422.
DMP Oxidation; Typical Procedure
1-Trimethylsilyl-3,3a,4,5-tetrahydro-2H-cyclopenta[c]acri-
dine-2,5-dione (4a)
1-Butyl-5-hydroxy-3,3a,4,5-tetrahydro-2H-cyclopenta[c]acri-
din-2-one (3b)
Yield: (100%); mp 47 °C.
IR (neat): 3327, 2925, 2854, 1702, 1661, 1489, 1027, 914 cm–1.
A solution of 15 w% DMP in CH2Cl2 (3.5 mL, 1.72 mmol) was add-
ed to a solution of alcohol (323 mg, 1.0 mmol) in CH2Cl2 (10 mL)
at r.t. under Ar. After 2 h of stirring, the reaction mixture was dilut-
ed with EtOAc and a mixture of aq 10% Na2S2O3 and sat. NaHCO3
solution (in 1:1 ratio) was added. The mixture was then stirred until
the phases were homogeneous (15 min). Extraction with EtOAc,
drying and evaporation gave the crude material, which was purified
by chromatography. Elution with a mixture of cyclohexane–EtOAc
(3:1) afforded the aldehyde (300 mg, 93%) as a yellow solid; mp
167–168 °C.
1H NMR (300 MHz, CDCl3): d = 0.97 (t, J = 7.2 Hz, 3 H), 1.40–1.74
(m, 4 H), 1.86 (dt, J = 3.0, 13.2 Hz, 1 H), 2.06–2.12 (br s, 1 H), 2.20
(dd, J = 3.0, 18.6 Hz, 1 H), 2.51 (ddd, J = 2.4, 3.9, 13.5 Hz, 1 H),
2.86 (dd, J = 6.3, 18.3 Hz, 1 H), 2.88–3.10 (m, 2 H), 3.55–3.68 (m,
1 H), 5.18 (m, 1 H), 7.58 (ddd, J = 1.2, 6.9, 8.4 Hz, 1 H), 7.75 (ddd,
J = 1.5, 6.9, 8.1 Hz, 1 H), 7.82 (d, J = 8.1 Hz, 1 H), 8.10 (d, J = 8.4
Hz, 1 H), 8.19 (s, 1 H)
13C NMR (75 MHz, CDCl3): d = 14.5 (CH3), 23.6 (CH2), 24.1
(CH2), 31.0 (CH2), 33.2 (CH), 38.0 (CH2), 41.4 (CH2), 68.2 (CH),
127.9 (CH), 128.0 (C), 128.1 (CH), 130.4 (CH), 130.5 (CH), 133.0
(C), 137.6 (CH), 144.5 (C), 148.5 (C), 151.0 (C), 162.9 (C), 209.5
(C).
IR (neat): 2968, 2950, 2894, 1686, 1273, 1157, 8567 cm–1.
1H NMR (300 MHz, CDCl3): d = 0.37 [s, 9 H, Si(CH3)3], 2.37 (dt,
J = 3.9, 18.3 Hz, 1 H), 2.70 (dd, J = 13.5, 16.5 Hz, 1 H), 2.91 (dd,
J = 6.9, 18.3 Hz, 1 H), 3.27 (dd, J = 5.1, 16.5 Hz, 1 H), 3.55–3.66
(m, 1 H), 7.68 (ddd, J = 1.2, 6.9, 8.4 Hz, 1 H), 7.90 (ddd, J = 1.5,
6.9, 8.4 Hz, 1 H), 8.02 (dd, J = 1.8, 8.4 Hz, 1 H), 8.16 (dd, J = 1.2,
8.4 Hz, 1 H), 8.93 (s, 1 H).
13C NMR (75 MHz, CDCl3): d = 0.2 (3 × CH3), 39.6 (CH), 43.3
(CH2), 45.5 (CH2), 126.4 (C), 127.6 (C), 128.4 (CH), 129.4 (CH),
129.8 (CH), 132.9 (CH), 137.1 (CH), 145.0 (C), 149.4 (C), 152.9
(C), 176.4 (C), 195.1 (C), 210.2 (C).
MS: m/z (%) = 308 (100) [MH+], 290 (7) [MH+ – H2O].
HRMS: m/z [MH+] calcd for C20H21NO2: 308.1651; found:
308.1656.
5-Hydroxy-1-phenyl-3,3a,4,5-tetrahydro-2H-cyclopenta[c]acri-
din-2-one (3c)
Yield: (81%); mp 98 °C.
MS: m/z (%) = 322 (100) [MH+], 306 (72) [MH+ – CH4].
IR (neat): 3364, 3056, 2908, 2359, 1676, 1487, 1224, 1151, 1034
cm–1.
HRMS: m/z [MH+] calcd for C19H20NO2Si: 322.1263; found:
322.1263.
1H NMR (300 MHz, CDCl3): d = 1.99 (dt, J = 3.6, 13.5 Hz, 1 H),
2.35 (dd, J = 3.6, 18.9 Hz, 1 H), 2.54 (ddd, J = 2.4, 3.9, 13.5 Hz, 1
H), 2.96 (dd, J = 6.6, 18.6 Hz, 1 H), 3.64–3.76 (m, 1 H), 5.15 (m, 1
H), 7.37–7.53 (m, 6 H), 7.55–7.65 (m, 2 H), 7.73 (d, J = 8.4 Hz, 1
H), 8.14 (s, 1 H).
13C NMR (75 MHz, CDCl3): d = 32.9 (CH2), 37.8 (CH), 41.4 (CH),
67.3 (CH2), 127.1 (CH), 127.2 (CH), 127.7 (CH), 127.8 (CH), 128.0
(C), 130.0 (CH), 130.3 (CH), 131.7 (C), 132.6 (C), 137.2 (CH),
140.7 (C), 147.4 (C), 148.9 (C), 162.9 (C), 209.5 (C).
1-Butyl-3,3a,4,5-tetrahydro-2H-cyclopenta[c]acridine-2,5-di-
one (4b)
Yield: (94%); mp 128 °C.
IR (neat): 2929, 2857, 1681, 1581, 1463, 1367, 1174, 1096, 935
cm–1.
1H NMR (300 MHz, CDCl3): d = 0.96 (t, J = 6.9 Hz, 3 H), 1.39–1.80
(m, 4 H), 2.31 (dd, J = 3.0, 18.6 Hz, 1 H), 2.62 (dd, J = 14.4, 16.2
Hz, 1 H), 2.90 (dd, J = 6.6, 17.2 Hz, 1 H), 2.90–3.05 (m, 2 H), 3.23
Synthesis 2005, No. 14, 2400–2406 © Thieme Stuttgart · New York