References and Notes
1
Hesse M.
Alkaloids - Nature’s Curse or Blessing?
Wiley-VCH;
Weinheim:
2002.
2a
Reha D.
Kabelac M.
Ryjacek F.
Sponer J.
Sponer JE.
Elstner M.
Suhai S.
Hobza P.
J. Am. Chem. Soc.
2002,
124:
3366
2b
Vendome J.
Letard S.
Martin F.
Svinarchuk F.
Dubreuil P.
Auclair C.
Le Bret M.
J. Med. Chem.
2005,
48:
6194
3
Yokoshima S.
Ueda T.
Kobayashi S.
Sato A.
Kuboyama T.
Tokuyama H.
Fukuyama T.
J. Am. Chem. Soc.
2002,
124:
2137
4 Review: Chen F.-E.
Huang J.
Chem. Rev.
2005,
ASAP : DOI 10.1021/cr040629a
Reviews:
5a
Robinson B.
Chem. Rev.
1969,
69:
227
5b
Hughes DL.
Org. Prep. Proced. Int.
1993,
25:
607
5c
Joule JA.
Science of Synthesis
Vol. 10:
Thomas J.
Thieme;
Stuttgart:
2001.
p.361
6a
Klioze SS.
Darmory FP.
J. Org. Chem.
1975,
40:
1588
6b
Miller FM.
Schinske WN.
J. Org. Chem.
1978,
43:
3384
6c
Freter K.
Fuchs V.
Pitner TP.
J. Org. Chem.
1983,
48:
4593
6d
Bonjoch J.
Casamitjana N.
Quirante J.
Rodriguez M.
Bosch J.
J. Org. Chem.
1987,
52:
267
6e
Zhao D.
Hughes DL.
Bender DR.
DeMarco AM.
Reider PJ.
J. Org. Chem.
1991,
56:
3001
7a
Miller FM.
Lohr RA.
J. Org. Chem.
1978,
43:
3388
7b
Hart DJ.
Wu SC.
Heterocycles
1993,
35:
135
7c
Atarashi S.
Choi J.-K.
Ha D.-C.
Hart DJ.
Kuzmich D.
Lee C.-S.
Ramesh S.
Wu SC.
J. Am. Chem. Soc.
1997,
119:
6226
8a
Macor JE.
Heterocycles
1990,
31:
993
8b
Shi H.-J.
Hu Y.-F.
Hu H.-W.
Acta Crystallogr., Sect. E
2004,
60:
o1381
Reviews:
9a
Christoffers J.
Chem.-Eur. J.
2003,
9:
4862
9b
Baro A.
Christoffers J. In Quaternary Stereocenters - Challenges and Solutions for Organic Synthesis
Christoffers J.
Baro A.
Wiley-VCH;
Weinheim:
2005.
p.83
10a
Christoffers J.
Schuster K.
Chirality
2003,
15:
777
10b
Christoffers J.
Scharl H.
Frey W.
Baro A.
Eur. J. Org. Chem.
2004,
2701
11
Ethyl 6,6a,7,8,9,10-Hexahydro-5
H
-cyclopenta[
b
]carb-azole-9a-carboxylate (
2a); Typical Procedure A mixture of ketone 1a (191 mg, 0.908 mmol), glacial AcOH (2.3 mL), TFA (0.80 mL), and PhNHNH2 (260 mg, 2.40 mmol) was stirred for 16 h at 100 °C in a tightly closed reaction vial. The mixture was added to ice-H2O (ca. 20 g) and the resulting emulsion was extracted with CH2Cl2 (3 × 10 mL). The combined organic layers were dried (MgSO4) and the solvent was evaporated. The residue was chromatographed twice (SiO2; hexanes-EtOAc, 5:1, R
f
0.36) to furnish carbazole derivative 2a (210 mg, 0.881 mmol, 97%) as light yellow crystals, mp 175-177 °C. 1H NMR (500 MHz, CDCl3): δ = 1.07 (t, J = 7.1 Hz, 3 H), 1.68-1.74 (m, 1 H), 1.83-1.90 (m, 2 H), 1.93-2.00 (m, 2 H), 2.17-2.23 (m, 2 H), 2.51 (dt, J = 15.1, 2.0 Hz, 1 H), 2.85 (ddd, J = 15.7, 5.7, 1.2 Hz, 1 H), 3.09 (br t, J = 13.7 Hz, 1 H), 3.59 (d, J = 15.0 Hz, 1 H), 3.88-3.93 (m, 1 H), 3.95-4.03 (m, 1 H), 7.06 (td, J = 7.4, 1.1 Hz, 1 H), 7.10 (td, J = 7.4, 1.2 Hz, 1 H), 7.25 (dd, J = 6.0, 1.1 Hz, 1 H), 7.46 (br d, J = 7.5 Hz, 1 H), 7.70 (br s, 1 H, NH). 13C{1H} NMR (75 MHz, CDCl3): δ = 175.59 (C), 136.40 (C), 134.88 (C), 127.50 (C), 120.95 (CH), 118.99 (CH), 117.72 (CH), 110.37 (CH), 110.02 (C), 59.84 (CH2), 53.72 (C), 46.11 (CH), 36.73 (CH2), 31.90 (CH2), 28.01 (CH2), 26.06 (CH2), 22.59 (CH2), 14.02 (CH3). MS (EI, 70 eV), m/z (%) = 283 (100) [M+]. Anal. calcd for C18H21NO2 (283.37): C, 76.30; H, 7.47; N, 4.94. Found: C, 76.09; H, 7.53; N, 4.83.
12 CCDC-286970 (2c) and CCDC-286971 (2a) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge at www.ccdc.cam.uk/conts/retrieving.html [or from the Cambridge Crystallographic Data Center, 12 Union Road, Cambridge CB2 1EZ, UK; fax: +44 (1223)336033; E-mail: deposit@ccdc.cam.ac.uk].
13
Ethyl 2,3,4,5,6,10c-Hexahydro-1
H
-cyclopenta[
c
]carb-azole-3a-carboxylate (
4) Yellow oil; R
f
0.30 (SiO2; hexanes-EtOAc, 5:1). 1H NMR (500 MHz, CDCl3): δ = 7.67 (br s, 1 H, NH), 7.50 (br d, J = 7.5 Hz, 1 H), 7.26 (br d, J = 7.5 Hz, 1 H), 7.10 (td, J = 7.1, 1.1 Hz, 1 H), 7.07 (td, J = 7.2, 1.1 Hz, 1 H), 4.11-4.19 (m, 1 H), 4.04-4.11 (m, 1 H), 3.76 (t, J = 8.3 Hz, 1 H), 2.78-2.88 (m, 1 H), 2.67 (dt, J = 16.4, 4.9 Hz, 1 H), 2.39-2.46 (m, 1 H), 2.29 (dt, J = 13.2, 4.8 Hz, 1 H), 2.17 (ddd, J = 12.6, 8.8, 6.0 Hz, 1 H), 1.86-1.96 (m, 1 H), 1.77-1.86 (m, 2 H), 1.61-1.77 (m, 2 H), 1.22 (t, J = 7.1 Hz, 3 H). 13C{1H} NMR (75 MHz, CDCl3): δ = 177.66 (C), 136.02 (C), 132.69 (C), 127.47 (C), 120.91 (CH), 118.92 (CH), 118.22 (CH), 112.16 (C), 110.53 (CH), 60.52 (CH2), 52.26 (C), 40.17 (CH), 36.86 (CH2), 33.04 (CH2), 29.45 (CH2), 24.82 (CH2), 20.75 (CH2), 14.15 (CH3). HRMS (EI, 70 eV): m/z calcd for C18H21NO2 [M+], 283.1572; found: 283.1574
14 Preparation of 3a by hydrogenation: Dauben WG.
McFarland JW.
Rogan JB.
J. Org. Chem.
1961,
26:
297
Preparation of 1b by hydrogenation:
15a
Gula MJ.
Spencer TA.
J. Org. Chem.
1980,
45:
805
15b
de la Puente ML.
Ley SV.
Simmonds MSJ.
Blaney WM.
J. Chem. Soc., Perkin Trans. 1
1996,
1523
16 Preparation of 1a-c by radical cyclization: Clive DLJ.
Postema MHD.
J. Chem. Soc., Chem. Commun.
1993,
429