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1
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0033850870
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Cacabelos, R.; Lombardi, A.; Fernandez-Novoa, L.; Corzo, L.; Perez, P. Laredo, M.; Pichel, V.; Hernandez, A.; Varela, M.; Figueroa, J.; Prous, J.; Windisch, M. Vigo, C. Drugs Today 2000, 36, 415-499.
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(2000)
Drugs Today
, vol.36
, pp. 415-499
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Cacabelos, R.1
Lombardi, A.2
Fernandez-Novoa, L.3
Corzo, L.4
Perez, P.5
Laredo, M.6
Pichel, V.7
Hernandez, A.8
Varela, M.9
Figueroa, J.10
Prous, J.11
Windisch, M.12
Vigo, C.13
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2
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0030918103
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Fukuyama, Y.; Kuwayama, A.; Minami, H. Chem. Pharm. Bull. 1997, 45, 947-949.
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(1997)
Chem. Pharm. Bull.
, vol.45
, pp. 947-949
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Fukuyama, Y.1
Kuwayama, A.2
Minami, H.3
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3
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0033583729
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(a) Nicolaou, K. C.; Pfefferkorn, J. A.; Kim, S.; Wei, H. X. J. Am. Chem. Soc. 1999, 121, 4724-4725.
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(1999)
J. Am. Chem. Soc.
, vol.121
, pp. 4724-4725
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Nicolaou, K.C.1
Pfefferkorn, J.A.2
Kim, S.3
Wei, H.X.4
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4
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-
0001027385
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-
(b) Nicolaou, K. C.; Pfefferkorn, J. A.; Cao, G.-Q.; Kim, S.; Kessabi, J. Org. Lett. 1999, 1, 807-810.
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(1999)
Org. Lett.
, vol.1
, pp. 807-810
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Nicolaou, K.C.1
Pfefferkorn, J.A.2
Cao, G.-Q.3
Kim, S.4
Kessabi, J.5
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5
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0033599540
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-
We developed general enantioselective catalysts for cyanosilylation of aldehydes: (a) Hamashima, Y.; Sawada, D.; Kanai, M.; Shibasaki, M. J. Am. Chem. Soc. 1999, 121, 2641-2642.
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(1999)
J. Am. Chem. Soc.
, vol.121
, pp. 2641-2642
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-
Hamashima, Y.1
Sawada, D.2
Kanai, M.3
Shibasaki, M.4
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6
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-
0034175598
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-
(b) Kanai, M.; Hamashima, Y.; Shibasaki, M. Tetrahedron Lett. 2000, 41, 2405-2409.
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(2000)
Tetrahedron Lett.
, vol.41
, pp. 2405-2409
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Kanai, M.1
Hamashima, Y.2
Shibasaki, M.3
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7
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-
0042042194
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-
Preliminary results indicated the feasibility of this idea (see the following scheme). Absolute configurations of the cyanohydrins are temporarily assigned from the preceding examples (ref 4b). (equation presented)
-
Preliminary results indicated the feasibility of this idea (see the following scheme). Absolute configurations of the cyanohydrins are temporarily assigned from the preceding examples (ref 4b). (equation presented)
-
-
-
-
8
-
-
0000569855
-
-
Other isomers emerged through a retro aldol-aldol sequence, if the reaction temperature was raised to slightly over -70°C or if there was a long reaction time (> 1 h). For an organocuprate conjugate addition - threo-selective aldol reaction, see: Heng, K. K.; Smith R. A. J. Tetrahedron 1979, 35, 425-435.
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(1979)
J. Tetrahedron
, vol.35
, pp. 425-435
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Heng, K.K.1
Smith, R.A.2
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9
-
-
0000477891
-
-
2AlCl) failed. For Lewis base-catalyzed cyanosilylation of aldehydes, see: (a) Evans, D. A.; Truesdale, L. K. Tetrahedron Lett. 1973, 49, 4929-4932.
-
(1973)
Tetrahedron Lett.
, vol.49
, pp. 4929-4932
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Evans, D.A.1
Truesdale, L.K.2
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11
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0042042195
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The diastereomers of 15 or 19 could be separated by column chromatography. We continued the synthesis as a diatereo-mixture, because the stereochemistry of C-4, -6, and -27 disappeared at the later stage
-
The diastereomers of 15 or 19 could be separated by column chromatography. We continued the synthesis as a diatereo-mixture, because the stereochemistry of C-4, -6, and -27 disappeared at the later stage.
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-
-
-
12
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-
0041540925
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-
Reactions using a normal higher order cuprate (CuCN/MeLi = 1/2) gave unpredictable results. On the other hand, reactions performed under the conditions described in the text were completely reproducible
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Reactions using a normal higher order cuprate (CuCN/MeLi = 1/2) gave unpredictable results. On the other hand, reactions performed under the conditions described in the text were completely reproducible.
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-
-
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13
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0142229025
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-
Kelly, D. R.; Roberts, S. M.; Newton, R. F. Synth. Commun. 1979, 9, 295-299.
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(1979)
Synth. Commun.
, vol.9
, pp. 295-299
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Kelly, D.R.1
Roberts, S.M.2
Newton, R.F.3
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14
-
-
0041540926
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-
The relative configuration was determined by X-ray analysis
-
The relative configuration was determined by X-ray analysis.
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-
-
-
15
-
-
0042042192
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-
These preliminary studies were conducted with the diastereomerically pure compound
-
These preliminary studies were conducted with the diastereomerically pure compound.
-
-
-
-
16
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-
0027314212
-
-
20 was prepared from the corresponding carboxylic acid: Grandjean, D.; Pale, P.; Chuche, J. Tetrahedron 1993, 49, 5225-5236.
-
(1993)
Tetrahedron
, vol.49
, pp. 5225-5236
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Grandjean, D.1
Pale, P.2
Chuche, J.3
-
17
-
-
0042042191
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-
The possibility that the reaction proceeded through a dianion could be excluded because the reaction using 1.2 equiv of KO′Bu under the optimized conditions (see below) gave 23 + 24 in 43% yield
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The possibility that the reaction proceeded through a dianion could be excluded because the reaction using 1.2 equiv of KO′Bu under the optimized conditions (see below) gave 23 + 24 in 43% yield.
-
-
-
-
18
-
-
0041540924
-
-
The structure of 23 was unequivocally determined by X-ray crystallography. See Supporting Information for details
-
The structure of 23 was unequivocally determined by X-ray crystallography. See Supporting Information for details.
-
-
-
-
19
-
-
0042042193
-
-
Direct formation of the lithium enolate with LiO′Bu failed due to the lower basicity of the base
-
Direct formation of the lithium enolate with LiO′Bu failed due to the lower basicity of the base.
-
-
-
-
20
-
-
0043043882
-
-
Preliminary studies to reverse the stereoselectivity of this one-pot cyclization revealed that employing a cyclic carbonate for the protecting group of the diol instead of the acetonide gave an ca. 1:1 mixture of diastereomers. Although the origin of the high stereoselectivity in the case of acetonide-protected 19 is not clear, coordination of the 18-oxygen atom to the lithium atom of the enolate might fix the substrate conformation to block the entry of the electrophile from the β-side
-
Preliminary studies to reverse the stereoselectivity of this one-pot cyclization revealed that employing a cyclic carbonate for the protecting group of the diol instead of the acetonide gave an ca. 1:1 mixture of diastereomers. Although the origin of the high stereoselectivity in the case of acetonide-protected 19 is not clear, coordination of the 18-oxygen atom to the lithium atom of the enolate might fix the substrate conformation to block the entry of the electrophile from the β-side.
-
-
-
-
21
-
-
0043043884
-
-
These results indicated that the observed high stereoselectivity was derived from the C-18 configuration
-
These results indicated that the observed high stereoselectivity was derived from the C-18 configuration.
-
-
-
-
23
-
-
0000533773
-
-
We tried dimethylphenylsilyl, (diethylamino)diphenylsilyl, and dimethyl(o-methoxy)phenylsilyl groups, in addition to the pentamethyldisilyl group. The former two silyl groups could be introduced to 23 by conjugate addition in high yields (>90%); however, later conversions were unsuccessful. The third one (Lee, T. W.; Corey, E. J. Org. Lett. 2001, 3, 3337-3339) did not produce the conjugate adduct to 23.
-
(2001)
Org. Lett.
, vol.3
, pp. 3337-3339
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Lee, T.W.1
Corey, E.J.2
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24
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33748233150
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(a) Krohn, K.; Khanbabaee, K. Angew. Chem., Int. Ed. Engl. 1994, 33, 99-100.
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(1994)
Angew. Chem., Int. Ed. Engl.
, vol.33
, pp. 99-100
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Krohn, K.1
Khanbabaee, K.2
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25
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0033529811
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(b) Barret, A. G. M.; Head, J.; Smith, M. L.; Stock, N. S.; White, A. J. P.; Williams, D. J. J. Org. Chem. 1999, 64, 6005-6018.
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(1999)
J. Org. Chem.
, vol.64
, pp. 6005-6018
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Barret, A.G.M.1
Head, J.2
Smith, M.L.3
Stock, N.S.4
White, A.J.P.5
Williams, D.J.6
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27
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-
0025073031
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Fukuyama, T.; Lin, S.-C.; Li, L. J. Am. Chem. Soc. 1990, 112, 7050-7051.
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(1990)
J. Am. Chem. Soc.
, vol.112
, pp. 7050-7051
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Fukuyama, T.1
Lin, S.-C.2
Li, L.3
-
28
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-
84889488515
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-
Suginome, M.; Matsunaga, S.; Ho, Y. Synlett 1995, 941-942. Reaction under normal Tamao-oxidation conditions failed, possibly due to the instability of the intermediate alcohol under basic conditions.
-
(1995)
Synlett
, pp. 941-942
-
-
Suginome, M.1
Matsunaga, S.2
Ho, Y.3
-
31
-
-
0042542998
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-
The structure of 4 was unequivocally determined by X-ray crystallography. See the Supporting Information for details
-
The structure of 4 was unequivocally determined by X-ray crystallography. See the Supporting Information for details.
-
-
-
-
32
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0001279931
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-
Naruta, Y.; Nishigaichi, Y.; Maruyama, K. Org. Synth. 1992, 71, 118-124.
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(1992)
Org. Synth.
, vol.71
, pp. 118-124
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Naruta, Y.1
Nishigaichi, Y.2
Maruyama, K.3
-
33
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0032189003
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For examples, see: (a) Fukuyama, Y.; Minami, H.; Kuwayama, A. Phytochemistry 1998, 49, 853-857.
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(1998)
Phytochemistry
, vol.49
, pp. 853-857
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Fukuyama, Y.1
Minami, H.2
Kuwayama, A.3
-
34
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0000161668
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(b) Shan, M. D.; Hu, L. H.; Chen, Z. L. J. Nat. Prod. 2001, 64, 127-130.
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(2001)
J. Nat. Prod.
, vol.64
, pp. 127-130
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-
Shan, M.D.1
Hu, L.H.2
Chen, Z.L.3
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