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DOI: 10.1055/s-2002-31910
Efficient Syntheses of Angularly Fused Triquinanes via β-Amino-Substituted α,β-Unsaturated Fischer-Carbene Complexes
Publication History
Publication Date:
07 February 2007 (online)
Abstract
Formal [3+2] cycloadditions of the carbene ligand in the new (3-dimethylamino-1-alkoxyalkenylidene)pentacarbonylchromium complexes 5 and 14 both with cyclopropyl substituents in the 3-position, onto alkynes give 5-dimethylamino-3-ethoxycyclopentadienes 6 and 15a-f, the latter along with regioisomers 16a-d, in good yields (55-72%). Treatment of these with hydrochloric acid liberates two carbonyl groups in each of them, and the resulting 5-dimethylaminocyclopent-1-en-3-ones 7 and 17a-c/18a-c, under basic conditions, undergo a cascade of two cyclizations, to yield angularly fused triquinanes 10 (68%) and 23a-c (30-97%). The overall procedure consists of four operational steps and produces cyclopropane-annelated tricyclo[6.3.0.0 [1] [5] ]undecane skeletons from two different alkynes each in 22-47% overall yield.
Key words
carbenechromium complexes - cycloadditions - cyclopentadienones - cascade reactions - spiro[4.4]nonenones - triquinanes
- Reviews see:
-
1a
Paquette LA. Top. Curr. Chem. 1979, 79: 41 -
1b
Paquette LA. Top. Curr. Chem. 1984, 119: 1 -
1c
Paquette LA.Doherty AM. Polyquinane Chemistry Springer; Berlin: 1987. - 2
de Meijere A. Pure Appl. Chem. 1996, 68: 61 - 3
de Meijere A.Schirmer H.Duetsch M. Angew. Chem. Int. Ed. 2000, 39: 3964 ; Angew. Chem. 2000, 112, 4124 - 4
Flynn BL.Funke FJ.Silveira CC.de Meijere A. Synlett 1995, 1007 - 5
Schirmer H.Funke FJ.Müller S.Noltemeyer M.Flynn BL.de Meijere A. Eur. J. Org. Chem. 1999, 2025 - 6 Review:
Metha G.Srikrishna A. Chem. Rev. 1997, 97: 671 - The alkyne 4 has been prepared from (+)-carene previously:
-
7a
Donkervoort JG.Gordon AR.Johnstone C.Kerr WJ.Lange U. Tetrahedron 1996, 52: 7391 -
7b
Better yields of 4, however, were obtained by modifying the reported procedure in two steps. Firstly, the cyclopropane-carboxylic acid 2 was converted to the cyclopropyl methyl ketone according to the protocol of House et al., [8] and secondly the protocol of Negishi et al. [9] was applied to convert the methyl ketone to the terminal alkyne via the enol phosphate.
- 8
Bare TM.House HO. Org. Synth. 1969, 49: 81 - 9
Negishi E.-I.King AO.Tour JM. Org. Synth. 1985, 64: 44 - 13 A 1,1-disubstituted cyclopropane moiety can actually also serve as a masked gem-dimethyl group, which can be unmasked by catalytic hydrogenation. Cf.:
Piers E.Karunaratne V. Tetrahedron 1989, 45: 1089 - 14
Militzer H.-C.Schömenauer S.Otte C.Puls C.Hain J.Bräse S.de Meijere A. Synthesis 1993, 998 - 15
Schizuri Y.Shojiro M.Ohkubo M.Yamamura S. Tetrahedron Lett. 1990, 7167
References and Notes
All new compounds were fully characterized by IR, NMR (1H, 13C) mass spectra as well as correct elemental analyses. Spectroscopic data of representative examples are as follows:
Pentacarbonyl[(2
E
/
Z
)-3-dimethylamino-3-{(1′
S
,3′
R
)-
cis
-2′,2′-dimethyl-3′-[2′′-(2′′′-methyl-[1′′′,3′′′]-dioxolan-2′′′-yl)ethyl]cyclopropyl}-1-ethoxy-2-propen-1-yliden]-chromium(5): Rf = 0.56 (Z-isomer), Rf = 0.39 (E-isomer), Et2O (10:1)], yellow crystals, mp 75 °C. IR (KBr): 2980 cm-1 (C-H), 2912 (C-H), 2769 (C-H), 2044 (C=O), 1969 (C=O), 1889 (C=O), 1527 (C=C), 1431, 1376, 1317, 1254, 1148, 1094, 1069, 1038, 982, 923, 869, 782, 671. 1H NMR (250 MHz, CDCl3): δ = 0.96 (s, 3 H, CH3), 1.01 (mc, 1 H, 3′-H), 1.24 (s, 3 H, CH3), 1.29 (s, 3 H, CH3), 1.35 (mc, 1 H, 1′-H), 1.44 (t, 3
J = 7.0 Hz, 3 H, OCH2CH
3), 1.44-1.73 (m, 4 H, 4′′-H, 5′′-H), 3.13 [bs, 6 H, N(CH3)2], 3.92 (mc, 4 H, OCH2CH2O), 4.65 (q, 3
J = 7.0 Hz, 2 H, OCH
2CH3), 6.25 (s, 1 H, 2H). 13C NMR (62.9 MHz, CDCl3, plus DEPT): δ = 15.2 (+, C-3′), 15.5 (+, OCH2
CH3), 20.8 (-, C-1′′), 23.2 (Cquat., C-2′), 23.6 (+, CH3), 28.5 (+, CH3), 30.1 (+, C-1′), 32.3 (+, CH3), 38.8 (-, C-2′′), 41.5 [+, N(CH3)2], 64.4 (-, OCH2CH2O), 72.9 (-, OCH2CH3), 109.4 (Cquat, C-2′′′), 119.8 (+, C-2), 159.7 (Cquat, C-3), 219.3, 224.4 (Cquat, C=O), 279.9 (Cquat, C-1). - MS (70 eV), m/z (%): 501(3) [M+], 473(13) [M+ - CO], 445(5) [M+ - 2CO], 417(6) [M+ - 3 CO], 389(2) [M+ - 4 CO], 361(100) [M+ - 5 CO], 220(21), 204(29), 191(64), 95(25), 87(28), 52(47) [Cr+], 43(34).
4,5,11,11-Tetramethyltetracyclo[6.4.0.0
[1]
[5]
.0
[10]
[12]
]-dodec-an-3,7-dione(10): Rf = 0.25 in Pentane-Et2O (3:1, colorless crystals, mp 101 °C. IR (KBr): 3010 cm-1 (C-H), 2957 (C-H), 2938 (C-H), 2877 (C-H), 1732 (C=O), 1456, 1390, 1376, 1339, 1266, 1206, 1191, 1124, 1100, 1083, 1008, 931, 895, 841, 647, 542, 465. 1H NMR (500 MHz, CDCl3): δ = 0.99 (s, 3 H, CH3), 1.01 (s, 3 H, CH3), 1.02 (d, 3
J = 7.0 Hz, 3 H, CH3), 1.17 (s, 3 H, CH3), 1.23 (dd, 3
J = 6.4, 3
J = 6.4 Hz, 1 H, 10-H), 1.29 (d, 3
J = 6.4 Hz, 1 H, 12-H), 1.88 (ddd, 2
J = 13.8, 3
J = 8.0, 3
J = 6.4 Hz, 1 H, 9-H), 2.01 (AB, d, 2
J = 18.1 Hz, 1 H, 6-H), 2.08 (AB, d, 2
J = 18.1 Hz, 1 H, 6-H), 2.16 (dd, 2
J = 13.8, 3
J = 10.7 Hz, 1 H, 9-H), 2.38 (dq, 3
J = 7.0, 4
J = 1.7 Hz, 1 H, 4-H), 2.40 (AB, d, 2
J = 19.9 Hz, 1 H, 2-H), 2.42 (dd, 3
J = 10.7, 3
J = 8.0 Hz, 1 H, 8-H), 2.78 (dd, 2
J = 19.9, 4
J = 1.7 Hz, 1 H, 2-H). 13C NMR (62.9 MHz, CDCl3, plus DEPT): δ = 9.2 (+, CH3), 16.3 (+, CH3), 19.3 (Cquat, C-11), 21.5 (+, CH3), 27.9 (+, CH3), 29.6 (-, C-9), 30.8 (+, C-10), 37.6 (+, C-12), 48.0 (-, C-2), 49.0 (-, C-6), 50.0 (Cquat, C-5), 53.2 (+, C-4), 56.3 (Cquart, C-1), 60.9 (+, C-8), 217.9, 218.7 (Cquat, C-3, C-7). MS (70 eV), m/z (%): 246(24) [M+], 218(31) [M+ - CO], 203(11), 190(8), 175(17), 161(8), 148(56), 133(9), 121(100), 105(55).
4,7-Dimethylspiro{cyclopropane-1,11-tricyclo-[6.4.0.0
[1]
[5]
]undeca-4,6-dien-3-one}(23a): Rf = 0.75 in Et2O, colorless oil. IR(film): 3066 cm-1 (C-H), 2948 (C-H), 2915 (C-H), 2854 (C-H), 1695 (C=O), 1641 (C=O), 1587, 1436, 1336, 1246, 1014, 971, 843, 728, 668, 592. 1H NMR (500 MHz, CDCl3): δ = -0.65 to -0.25 (m, 1 H, cPr-H), 0.08-0.13 (m, 1 H, cPr-H) 0.16-0.20 (m, 1 H, cPr-H) 0.33-0.38 (m, 1 H, cPr-H), 1.20-1.30 (m, 1 H, 10-H), 1.65 (s, 3 H, CH3) 1.63-1.73 (m, 1 H, 10-H), 1.92 (s, 3 H, CH3), 1.96-2.08 (m, 2 H, 9-H), 2.32 (AB, d, 2
J = 16 Hz, 1 H, 2-H), 2.48 (AB, d, 2
J = 16 Hz, 1 H, 2-H), 3.00-3.07 (m, 1 H, 8-H), 6.10 (s, 1 H, 6-H). 13C NMR (62.9 MHz, CDCl3, plus, DEPT): 4.9 (-, cPr-C), 8.7 (+, CH3), 14.1 (-, cPr-C), 16.5 (+, CH3), 26.5 (-, C-10), 31.8 (Cquat, C-11), 36.9 (& ndash;, C-9), 48.7 (-, C-2), 58.1 (+, C-8), 60.0 (Cquat, C-1), 120.9 (+, C-6), 124.8 (Cquat, C-5), 162.8 (Cquat, C-7), 179.5 (Cquat, C-4), 209.6 (Cquat, C-3). MS (70 eV), m/z (%): 214(100) [M+], 199(19) [M+ - CH3], 185(16) [M+ - C2H5O], 171(35) [M+ - C3H7O], 159(38), 143(21), 132(18), 115(17), 91(16), 77(10), 65(4), 53(4), 41(4).
Milic, J.; Schirmer, H.; de Meijere, A. unpublished results.
12Crystallographic data for the angular triquinanes 10 and 23c have been deposited with the Cambridge Crystallographic Data Centre as supplementary publications no. CCDC-180879(10) and CCDC-180718(23c). Copies of the data can be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax: +44(1223)336033; e-mail: deposit@ccdc.cam.ac.uk).