-
2
-
-
0141856186
-
-
b) K. R. Crawford, S. K. Bur, C. S. Straub, A. Padwa, Org. Lett. 2003, 5, 3337;
-
(2003)
Org. Lett
, vol.5
, pp. 3337
-
-
Crawford, K.R.1
Bur, S.K.2
Straub, C.S.3
Padwa, A.4
-
5
-
-
0030836340
-
-
b) K. Fujii, K. Sivonen, K. Actachi, N. Kazuyoshi, Y. Shimizu, H. Sano, K. Hirayama, M. Suzuki, K. Harada, Tetrahedron Lett. 1997, 38, 5529;
-
(1997)
Tetrahedron Lett
, vol.38
, pp. 5529
-
-
Fujii, K.1
Sivonen, K.2
Actachi, K.3
Kazuyoshi, N.4
Shimizu, Y.5
Sano, H.6
Hirayama, K.7
Suzuki, M.8
Harada, K.9
-
6
-
-
57349166544
-
-
for a recent review on the chemistry of the aeruginosins, see
-
c) for a recent review on the chemistry of the aeruginosins, see: K. Ersmark, J. R. Del Vaile, S. Hanessian, Angew. Chem. 2008, 120, 1220;
-
(2008)
Angew. Chem
, vol.120
, pp. 1220
-
-
Ersmark, K.1
Del Vaile, J.R.2
Hanessian, S.3
-
8
-
-
70349969386
-
-
C. S. Schindler, C. R. J. Stephenson, E. M. Carreira, Angew. Chem. 2008, 120, 8984;
-
(2008)
Angew. Chem
, vol.120
, pp. 8984
-
-
Schindler, C.S.1
Stephenson, C.R.J.2
Carreira, E.M.3
-
14
-
-
0037239379
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-
and references therein;
-
c) M. Lautens, K. Fagnou, S. Hiebert, Acc. Chem. Res. 2003, 36, 48, and references therein;
-
(2003)
Acc. Chem. Res
, vol.36
, pp. 48
-
-
Lautens, M.1
Fagnou, K.2
Hiebert, S.3
-
15
-
-
0034647227
-
-
d) M. Lautens, K. Fagnou, T. Rovis, J. Am. Chem. Soc. 2000, 122, 5650.
-
(2000)
J. Am. Chem. Soc
, vol.122
, pp. 5650
-
-
Lautens, M.1
Fagnou, K.2
Rovis, T.3
-
18
-
-
0344861858
-
-
b) M. Lautens, K. Fagnou, D. Yang, J. Am. Chem. Soc. 2003, 125, 14884.
-
(2003)
J. Am. Chem. Soc
, vol.125
, pp. 14884
-
-
Lautens, M.1
Fagnou, K.2
Yang, D.3
-
19
-
-
62849108749
-
-
R. Webster, C. Böing, M. Lautens, J. Am. Chem. Soc. 2009, 131, 444.
-
(2009)
J. Am. Chem. Soc
, vol.131
, pp. 444
-
-
Webster, R.1
Böing, C.2
Lautens, M.3
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20
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70349950416
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The oxabicyclic substrates were prepared by an enantioselective Diels-Alder reaction of furan and bromoacrolein with the tryptophan-derived oxazaborolidine catalyst described by Corey and Loh see references [3] and [4, The L-tryptophan-derived catalyst was used for the reactions in entries 3 and 4 of Table 2 and entries 5 and 6 of Table 3; the D-tryptophan-derived catalyst was used for the reactions in entries 1 and 2 of Table 2 and entries 1-4 of Table 3
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The oxabicyclic substrates were prepared by an enantioselective Diels-Alder reaction of furan and bromoacrolein with the tryptophan-derived oxazaborolidine catalyst described by Corey and Loh (see references [3] and [4]). The L-tryptophan-derived catalyst was used for the reactions in entries 3 and 4 of Table 2 and entries 5 and 6 of Table 3; the D-tryptophan-derived catalyst was used for the reactions in entries 1 and 2 of Table 2 and entries 1-4 of Table 3.
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21
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70349965917
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To the best of our knowledge, there is only one example in the literature of the opening of an oxabicycloheptene by displacement of a bridging C - O bond, namely, the ring opening of 2-methylthio-7-oxabicyclo[2.2.1]heptene by silyl enol ethers in the presence of TBDMSOTf: I. Yamamoto, K. Narasaka, Chem. Lett. 1995, 1129. The ring opening proceeds by cleavage of the C - O bond, and net substitution occurs with retention of configuration. The stereochemical result underscores the fact that the reaction proceeds by heterolytic cleavage of the C - O bond to give a secondary carbocation, which is stabilized significantly by the vinyl sulfide.
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To the best of our knowledge, there is only one example in the literature of the opening of an oxabicycloheptene by displacement of a bridging C - O bond, namely, the ring opening of 2-methylthio-7-oxabicyclo[2.2.1]heptene by silyl enol ethers in the presence of TBDMSOTf: I. Yamamoto, K. Narasaka, Chem. Lett. 1995, 1129. The ring opening proceeds by cleavage of the C - O bond, and net substitution occurs with retention of configuration. The stereochemical result underscores the fact that the reaction proceeds by heterolytic cleavage of the C - O bond to give a secondary carbocation, which is stabilized significantly by the vinyl sulfide.
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22
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70349964238
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-3, T=223 K, reflections collected: 18793, independent reflections: 4693 (R(int) = 0.15), R(all) = 0.0678, wR(gt) = 0.1315. CCDC 721256 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data-request/cif.
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-3, T=223 K, reflections collected: 18793, independent reflections: 4693 (R(int) = 0.15), R(all) = 0.0678, wR(gt) = 0.1315. CCDC 721256 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data-request/cif.
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23
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70349946927
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ORTEP representation of the/-bromobenzoate ester of 20b (probability ellipsoids at 50%; Table 3, entry 5). Figure Presented.
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ORTEP representation of the/"-bromobenzoate ester of 20b (probability ellipsoids at 50%; Table 3, entry 5). Figure Presented.
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24
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70349964260
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We considered the mechanistic possibility of pinacol-type rearrangement sequences. However, the formation of the aminal product inevitably positions the tertiary hydroxy group at the other ring-fusion carbon atom. X-ray crystallographic analysis of the p-bromobenzoate ester of 20b proved critical in ruling out this option.
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We considered the mechanistic possibility of pinacol-type rearrangement sequences. However, the formation of the aminal product inevitably positions the tertiary hydroxy group at the other ring-fusion carbon atom. X-ray crystallographic analysis of the p-bromobenzoate ester of 20b proved critical in ruling out this option.
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25
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0041639631
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A. F. Bedford, A. E. Beezer, C. T. Mortimer, H. D. Springall, J. Chem. Soc. 1963, 3823.
-
(1963)
J. Chem. Soc
, pp. 3823
-
-
Bedford, A.F.1
Beezer, A.E.2
Mortimer, C.T.3
Springall, H.D.4
-
27
-
-
0024505783
-
-
b) C. Le Drian, E. Vieira, P. Vogel, Helv. Chim. Acta 1989, 72, 338;
-
(1989)
Helv. Chim. Acta
, vol.72
, pp. 338
-
-
Le Drian, C.1
Vieira, E.2
Vogel, P.3
-
30
-
-
84986364880
-
-
e) C. Nativi, J. L. Reymond, P. Vogel, Helv. Chim. Acta 1989, 72, 882;
-
(1989)
Helv. Chim. Acta
, vol.72
, pp. 882
-
-
Nativi, C.1
Reymond, J.L.2
Vogel, P.3
-
32
-
-
85082959690
-
-
g) T. Takahashi, A. Iyobe, Y. Arai, T. Koizumi, Synthesis 1989, 189;
-
(1989)
Synthesis
, pp. 189
-
-
Takahashi, T.1
Iyobe, A.2
Arai, Y.3
Koizumi, T.4
-
35
-
-
0028819003
-
-
A. Latvala, M. A. Oenur, T. Goezler, A. Linden, B. Kivcak, M. Hesse, Phytochemistry 1995, 39, 1229.
-
(1995)
Phytochemistry
, vol.39
, pp. 1229
-
-
Latvala, A.1
Oenur, M.A.2
Goezler, T.3
Linden, A.4
Kivcak, B.5
Hesse, M.6
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