-
1
-
-
33847799053
-
-
Reviews: a
-
Reviews: (a) Rao, Y. S. Chem. Rev. 1976, 76, 625.
-
(1976)
Chem. Rev
, vol.76
, pp. 625
-
-
Rao, Y.S.1
-
7
-
-
0001497456
-
-
Attanasi, O. A, Spinelli, D, Eds, Societa Chimica Italiana: Rome
-
(e) Rossi, R.; Bellina, F. In Targets in Heterocyclic Systems: Chemistry and Properties, Vol. 5; Attanasi, O. A.; Spinelli, D., Eds.; Societa Chimica Italiana: Rome, 2002, 169-198.
-
(2002)
Targets in Heterocyclic Systems: Chemistry and Properties
, vol.5
, pp. 169-198
-
-
Rossi, R.1
Bellina, F.2
-
9
-
-
0035959985
-
-
For recent syntheses of tetronic acids using Dieckmann condensations, see: b
-
For recent syntheses of tetronic acids using Dieckmann condensations, see: (b) Sodeoka, M.; Sampe, R.; Kojima, S.; Baba, Y.; Usui, T.; Ueda, K.; Osada, H. J. Med. Chem. 2001, 44, 3216.
-
(2001)
J. Med. Chem
, vol.44
, pp. 3216
-
-
Sodeoka, M.1
Sampe, R.2
Kojima, S.3
Baba, Y.4
Usui, T.5
Ueda, K.6
Osada, H.7
-
10
-
-
0033832542
-
-
(c) Mitsos, C. A.; Zografos, A. L.; Igglessi-Markopoulou, O. J. Org. Chem. 2000, 65, 5852.
-
(2000)
J. Org. Chem
, vol.65
, pp. 5852
-
-
Mitsos, C.A.1
Zografos, A.L.2
Igglessi-Markopoulou, O.3
-
11
-
-
33947543119
-
-
For a recent synthesis of tetronic acids by cyclization of γ-bromo-β-oxocarboxylic acids, see: d
-
For a recent synthesis of tetronic acids by cyclization of γ-bromo-β-oxocarboxylic acids, see: (d) Tabake, K.; Mase, N.; Nomoto, M.; Daicho, M.; Tauchi, T.; Yoda, H. J. Chem. Soc., Perkin Trans. 1 2002, 500.
-
(2002)
J. Chem. Soc., Perkin Trans. 1
, pp. 500
-
-
Tabake, K.1
Mase, N.2
Nomoto, M.3
Daicho, M.4
Tauchi, T.5
Yoda, H.6
-
12
-
-
0345381993
-
-
For a recent synthesis of tetronic acids by acid-treatment of the 2:1-adducts formed from aldehydes and methyl propiolate, see: e
-
For a recent synthesis of tetronic acids by acid-treatment of the 2:1-adducts formed from aldehydes and methyl propiolate, see: (e) Aragon, D. T.; López, G. V.; Garcia-Tellado, F.; Marrero-Tellado, J. J.; de Armas, P.; Terrero, D. J. Org. Chem. 2003, 68, 3363.
-
(2003)
J. Org. Chem
, vol.68
, pp. 3363
-
-
Aragon, D.T.1
López, G.V.2
Garcia-Tellado, F.3
Marrero-Tellado, J.J.4
de Armas, P.5
Terrero, D.6
-
13
-
-
0035974382
-
-
For a recent synthesis of tetronic acids by lactonization of γ-hydroxy-β-oxo esters resulting from the [2,3]-Wittig rearrangement of γ-(allyloxy)-β-oxo esters, see: (f) Pévet, I, Meyer, C, Cossy, J. Tetrahedron Lett. 2001, 42, 5215
-
For a recent synthesis of tetronic acids by lactonization of γ-hydroxy-β-oxo esters resulting from the [2,3]-Wittig rearrangement of γ-(allyloxy)-β-oxo esters, see: (f) Pévet, I.; Meyer, C.; Cossy, J. Tetrahedron Lett. 2001, 42, 5215.
-
-
-
-
14
-
-
15944372237
-
-
For a recent synthesis of tetronic acids by the oxidation of β-hydroxy-γ-butyrolactones, see: g
-
For a recent synthesis of tetronic acids by the oxidation of β-hydroxy-γ-butyrolactones, see: (g) Kapferer, T.; Brückner, R.; Herzig, A.; König, W. A. Chem. Eur. J. 2005, 11, 2154.
-
(2005)
Chem. Eur. J
, vol.11
, pp. 2154
-
-
Kapferer, T.1
Brückner, R.2
Herzig, A.3
König, W.A.4
-
15
-
-
0034974653
-
-
Section 7. Review: a
-
Review: (a) Brückner, R. Curr. Org. Chem. 2001, 5, 679, Section 7.
-
(2001)
Curr. Org. Chem
, vol.5
, pp. 679
-
-
Brückner, R.1
-
16
-
-
0034005721
-
-
Recent synthesis of pulvinones using methodology from ref. 9: (b) Klostermeyer, D.; Knops, L.; Sindlinger, T.; Polborn, K.; Steglich, W. Eur. J. Org. Chem. 2000, 4, 603.
-
Recent synthesis of pulvinones using methodology from ref. 9: (b) Klostermeyer, D.; Knops, L.; Sindlinger, T.; Polborn, K.; Steglich, W. Eur. J. Org. Chem. 2000, 4, 603.
-
-
-
-
17
-
-
0034974653
-
-
Sections 8-9. Reviews: a
-
Reviews: (a) Brückner, R. Curr. Org. Chem. 2001, 5, 679, Sections 8-9.
-
(2001)
Curr. Org. Chem
, vol.5
, pp. 679
-
-
Brückner, R.1
-
18
-
-
0018174289
-
-
Pattenden, G. Prog. Chem. Nat. Prod. 1978, 35, 133, Sections III.1, III.3, and IV.2.
-
(b) Pattenden, G. Prog. Chem. Nat. Prod. 1978, 35, 133, Sections III.1, III.3, and IV.2.
-
-
-
-
19
-
-
0023070031
-
-
Gill, M.; Steglich, W. Prog. Chem. Nat. Prod. 1987, 51, 1, Section 2.1.3.
-
(c) Gill, M.; Steglich, W. Prog. Chem. Nat. Prod. 1987, 51, 1, Section 2.1.3.
-
-
-
-
20
-
-
13444263395
-
-
Syntheses of pulvinic acids by Suzuki couplings with tetronic esters containing a triflate substituent at Cβ: (d) Ahmed, Z, Langer, P. Tetrahedron 2005, 61, 2055
-
Syntheses of pulvinic acids by Suzuki couplings with tetronic esters containing a triflate substituent at Cβ: (d) Ahmed, Z.; Langer, P. Tetrahedron 2005, 61, 2055.
-
-
-
-
21
-
-
2442666554
-
-
and literature cited therein
-
(e) Ahmed, Z.; Langer, P. J. Org. Chem. 2004, 64, 3753; and literature cited therein.
-
(2004)
J. Org. Chem
, vol.64
, pp. 3753
-
-
Ahmed, Z.1
Langer, P.2
-
22
-
-
13844316983
-
-
For more applications of Langer's methodology, see: f
-
For more applications of Langer's methodology, see: (f) Heurtaux, B.; Lion, C.; Le Gall, T.; Mioskowski, C. J. Org. Chem. 2005, 70, 1474.
-
(2005)
J. Org. Chem
, vol.70
, pp. 1474
-
-
Heurtaux, B.1
Lion, C.2
Le Gall, T.3
Mioskowski, C.4
-
23
-
-
0037451428
-
-
(g) Desage-El Mur, M.; Nowaczyk, S.; Le Gall, T.; Mioskowski, C.; Amekraz, B.; Moulin, C. Angew. Chem. Int. Ed. 2003, 42, 1289;
-
(2003)
Angew. Chem. Int. Ed
, vol.42
, pp. 1289
-
-
Desage-El Mur, M.1
Nowaczyk, S.2
Le Gall, T.3
Mioskowski, C.4
Amekraz, B.5
Moulin, C.6
-
24
-
-
33846551173
-
-
Angew. Chem., 2003, 115, 1327.
-
(2003)
Chem
, vol.115
, pp. 1327
-
-
Angew1
-
28
-
-
37049092048
-
-
Campbell, A. C.; Maidment, M. S.; Pick, J. H.; Stevenson, D. F. M. J. Chem. Soc, Perkin Trans. 1 1985, 1567.
-
(1985)
J. Chem. Soc, Perkin Trans. 1
, pp. 1567
-
-
Campbell, A.C.1
Maidment, M.S.2
Pick, J.H.3
Stevenson, D.F.M.4
-
29
-
-
33947494406
-
-
11
-
11
-
-
-
-
30
-
-
84970616552
-
-
Gill, M.; Kiefel, M. J.; Lally, D. A.; Ten, A. Aust. J. Chem. 1990, 43, 1497.
-
(1990)
Aust. J. Chem
, vol.43
, pp. 1497
-
-
Gill, M.1
Kiefel, M.J.2
Lally, D.A.3
Ten, A.4
-
31
-
-
33947513134
-
-
Method is given in ref. 9
-
Method is given in ref. 9.
-
-
-
-
32
-
-
33947510366
-
-
9
-
9
-
-
-
-
33
-
-
0011286587
-
-
Tetronic ester 10a was obtained by the base-mediated condensation of (4-methoxyphenyl)acetonitrile with diethyl oxalate followed by O-methylation of the enol and anhydride formation: Knight, D. W.; Pattenden, G. J. Chem. Soc., Perkin Trans. 1 1979, 62. Hydride reduction provided a separable mixture of 10a and hydroxy-10a which was once more reduced giving more 10a.
-
Tetronic ester 10a was obtained by the base-mediated condensation of (4-methoxyphenyl)acetonitrile with diethyl oxalate followed by O-methylation of the enol and anhydride formation: Knight, D. W.; Pattenden, G. J. Chem. Soc., Perkin Trans. 1 1979, 62. Hydride reduction provided a separable mixture of 10a and hydroxy-10a which was once more reduced giving more 10a.
-
-
-
-
35
-
-
33947544881
-
-
9
-
9
-
-
-
-
36
-
-
27744484480
-
-
Antane, S.; Caufield, C. E.; Hu, W.; Keeney, D.; Labthavikul, P.; Morris, K.; Naughton, S. M.; Petersen, P. J.; Rasmussen, B. A.; Singh, G.; Yang, Y. Bioorg. Med. Chem. Lett. 2006, 16, 176.
-
(2006)
Bioorg. Med. Chem. Lett
, vol.16
, pp. 176
-
-
Antane, S.1
Caufield, C.E.2
Hu, W.3
Keeney, D.4
Labthavikul, P.5
Morris, K.6
Naughton, S.M.7
Petersen, P.J.8
Rasmussen, B.A.9
Singh, G.10
Yang, Y.11
-
38
-
-
33947512540
-
-
Caufield, C. E.; Antane, S. A.; Morris, K. M.; Naughton, S. M.; Quagliato, D. A.; Andrae, P. M.; Enos, A.; Chiarello, J. F. WO 2005/019196, 2005.
-
Caufield, C. E.; Antane, S. A.; Morris, K. M.; Naughton, S. M.; Quagliato, D. A.; Andrae, P. M.; Enos, A.; Chiarello, J. F. WO 2005/019196, 2005.
-
-
-
-
39
-
-
37049096391
-
-
Ramage, R.; Griffiths, G. J.; Shutt, F. E.; Sweeney, J. N. A. J. Chem. Soc, Perkin Trans. 1 1984, 1531.
-
(1984)
J. Chem. Soc, Perkin Trans. 1
, pp. 1531
-
-
Ramage, R.1
Griffiths, G.J.2
Shutt, F.E.3
Sweeney, J.N.A.4
-
40
-
-
37049099001
-
-
Ramage, R.; Griffiths, G. J.; Shutt, F. E.; Sweeney, J. N. A. J. Chem. Soc, Perkin Trans. 1 1984, 1539.
-
(1984)
J. Chem. Soc, Perkin Trans. 1
, pp. 1539
-
-
Ramage, R.1
Griffiths, G.J.2
Shutt, F.E.3
Sweeney, J.N.A.4
-
41
-
-
33947516085
-
-
Each of Ramage et al.'s three pulvinones emerged from a slightly different protocol:21 (Z)-21a: Scheme 3, steps (e 1) and (e2, there appeared to be no addition of acid other than in one of the two recrystallization procedures, Z, 21b was obtained from PhCHO and lithio-20a in 71% yield analogously as described in (e1, step (e2) was replaced by no evaporation of THF, adding H2O, refluxing (30 min, evaporating the solvents, adding Et2O-H2O (1:1, keeping the aqueous phase, adding HCl (to pH 1, isolating the resulting solid; (Z)-8b was obtained from PhCHO and the lithium enolate of methyl phenylacetate in 94% yield analogously as described in (e1, step (e2) was replaced by evaporating THF, adding Et2O-H2O (1:1, keeping the aqueous phase, adding HCl to pH 1, isolating the resulting solid. We followed a
-
2O (1:1), etc.
-
-
-
-
42
-
-
0032513713
-
-
(a) Burk, M. J.; Kalberg, C. S.; Pizzano, A. J. Am. Chem. Soc. 1998, 120, 4345.
-
(1998)
J. Am. Chem. Soc
, vol.120
, pp. 4345
-
-
Burk, M.J.1
Kalberg, C.S.2
Pizzano, A.3
-
43
-
-
33947514658
-
-
Analogous addition of dialkyl phosphites/dialkyl H-phosphonates to butyl glyoxylate: (b) Pudovik, A. N.; Gur'yanova, I. V. J. Gen. Chem. USSR (Engl. Transl.) 1967, 37, 1566;
-
Analogous addition of dialkyl phosphites/dialkyl H-phosphonates to butyl glyoxylate: (b) Pudovik, A. N.; Gur'yanova, I. V. J. Gen. Chem. USSR (Engl. Transl.) 1967, 37, 1566;
-
-
-
-
44
-
-
33947508531
-
-
Zh. Obshch. Khim., 1967, 37, 1649.
-
(1967)
Obshch. Khim
, vol.37
, pp. 1649
-
-
Zh1
-
45
-
-
0028109553
-
-
Analogous addition of diethyl phosphite/diethyl H-phosphonate to ethyl glyoxylate, liberated from its hemi(ethyl acetal): (c) Schmidt, U.; Langner, J.; Kirschbaum, B.; Braun, C. Synthesis 1994, 1138.
-
Analogous addition of diethyl phosphite/diethyl H-phosphonate to ethyl glyoxylate, liberated from its hemi(ethyl acetal): (c) Schmidt, U.; Langner, J.; Kirschbaum, B.; Braun, C. Synthesis 1994, 1138.
-
-
-
-
46
-
-
84985532528
-
-
Method is given in: Gerlach, U.; Hünig, S. Angew. Chem., Int. Ed. Engl. 1987, 26, 1283;
-
Method is given in: Gerlach, U.; Hünig, S. Angew. Chem., Int. Ed. Engl. 1987, 26, 1283;
-
-
-
-
47
-
-
33947522976
-
-
Angew. Chem. 1987, 99, 1323.
-
(1987)
Chem
, vol.99
, pp. 1323
-
-
Angew1
-
48
-
-
0002714675
-
-
Still, W. C.; Kahn, M.; Mitra, A. J. Org. Chem. 1978, 43, 2923.
-
(1978)
J. Org. Chem
, vol.43
, pp. 2923
-
-
Still, W.C.1
Kahn, M.2
Mitra, A.3
-
49
-
-
0000476716
-
-
Blanchette, M. A.; Choy, W.; Davis, J. T.; Essenfeld, A. P.; Masamune, S.; Roush, W. R. Tetrahedron Lett. 1984, 25, 2183.
-
(1984)
Tetrahedron Lett
, vol.25
, pp. 2183
-
-
Blanchette, M.A.1
Choy, W.2
Davis, J.T.3
Essenfeld, A.P.4
Masamune, S.5
Roush, W.R.6
-
50
-
-
0034725908
-
-
2Et undergoing Z-selective Horner-Wadsworth-Emmons reactions with α-chiral aldehydes in the presence of NaI, DBU, and HMPA: Ando, K.; Oishi, T.; Hirama, M.; Hiroali, O.; Ibuka, T. J. Org. Chem. 2000, 65, 4745; in order to minimize health hazards, we replaced HMPA by DMPU.
-
2Et undergoing Z-selective Horner-Wadsworth-Emmons reactions with α-chiral aldehydes in the presence of NaI, DBU, and HMPA: Ando, K.; Oishi, T.; Hirama, M.; Hiroali, O.; Ibuka, T. J. Org. Chem. 2000, 65, 4745; in order to minimize health hazards, we replaced HMPA by DMPU.
-
-
-
-
52
-
-
0006004578
-
-
Kokin, K.; Iitake, K.-I.; Takaguchi, Y.; Aoyama, H.; Hayashi, S.; Motoyoshiya, J. Phosphorus, Sulfur Silicon Relat. Elem. 1998, 133, 21.
-
(1998)
Phosphorus, Sulfur Silicon Relat. Elem
, vol.133
, pp. 21
-
-
Kokin, K.1
Iitake, K.-I.2
Takaguchi, Y.3
Aoyama, H.4
Hayashi, S.5
Motoyoshiya, J.6
-
53
-
-
0035804954
-
-
Methyl 2-(tert-butyldimethylsiloxy)-2-(dimethoxyphosphoryl) acetate, upon deprotonation with LDA in pure THF, and 4-methoxy-2- (methoxymethoxy)benzaldehyde condense with seemingly perfect Z/E selectivity: Boehlow, T. R.; Harburn, J. J.; Spilling, C. D. J. Org. Chem. 2001, 66, 3111.
-
Methyl 2-(tert-butyldimethylsiloxy)-2-(dimethoxyphosphoryl) acetate, upon deprotonation with LDA in pure THF, and 4-methoxy-2- (methoxymethoxy)benzaldehyde condense with seemingly perfect Z/E selectivity: Boehlow, T. R.; Harburn, J. J.; Spilling, C. D. J. Org. Chem. 2001, 66, 3111.
-
-
-
-
55
-
-
0022253211
-
-
Related finding: Boschelli, D.; Takemasa, T.; Nishitani, Y.; Masamune, S. Tetrahedron Lett. 1985, 26, 5239.
-
(b) Related finding: Boschelli, D.; Takemasa, T.; Nishitani, Y.; Masamune, S. Tetrahedron Lett. 1985, 26, 5239.
-
-
-
-
57
-
-
33947542843
-
-
In a related condensation using lithium diisopropylamide/ ester 26/dioxolanone 25c, we ascertained that the yield of pulvinone 28 decreased from 60% to 40% upon changing the reactant ratio from 2.5:2.5:1 to 2.5:1.25:1 (Scheme 4). The analogous condensation using lithium diisopropylamide/ carboxylic acid 27/dioxolanone 25c (2.2:1.1:1 ratio of the reactants) did not give pulvinone 28 under the conditions otherwise identical to those of Table 5 (Kaczybura, N. Dissertation; Universität Freiburg: Germany, 2005). (Chemical Equation Presented)
-
In a related condensation using lithium diisopropylamide/ ester 26/dioxolanone 25c, we ascertained that the yield of pulvinone 28 decreased from 60% to 40% upon changing the reactant ratio from 2.5:2.5:1 to 2.5:1.25:1 (Scheme 4). The analogous condensation using lithium diisopropylamide/ carboxylic acid 27/dioxolanone 25c (2.2:1.1:1 ratio of the reactants) did not give pulvinone 28 under the conditions otherwise identical to those of Table 5 (Kaczybura, N. Dissertation; Universität Freiburg: Germany, 2005). (Chemical Equation Presented)
-
-
-
-
58
-
-
0342634209
-
-
Earlier description of pulvinone (Z)-8f: Ojima, N.; Takenaka, S.; Seto, S. Phytochemistry 1973, 12, 2527.
-
Earlier description of pulvinone (Z)-8f: Ojima, N.; Takenaka, S.; Seto, S. Phytochemistry 1973, 12, 2527.
-
-
-
-
59
-
-
37049127697
-
-
Pulvinone (Z)-8j was synthesized in a mixture which also contained the isomeric pulvinone (Z)-5-(3,4-dimethoxybenzylidene)-4- hydroxy-3-(4-methoxyphenyl)furan-2(5H)-one: Edwards, R. L.; Gill, M. J. Chem. Soc., Perkin Trans. 1 1973, 1921.
-
Pulvinone (Z)-8j was synthesized in a mixture which also contained the isomeric pulvinone (Z)-5-(3,4-dimethoxybenzylidene)-4- hydroxy-3-(4-methoxyphenyl)furan-2(5H)-one: Edwards, R. L.; Gill, M. J. Chem. Soc., Perkin Trans. 1 1973, 1921.
-
-
-
-
60
-
-
33947546988
-
-
We could not extend our approach to a synthesis of pulvinic acids 32 and 33. While dioxolanone 31 was accessible by a Horner-Wadsworth-Emmons reaction between phosphonate 24b and α-oxo ester 29 (79% yield), it did not react with the ester enolate 30 by Claisen condensation/transesterification (Scheme 5). (Chemical Equation Presented)
-
We could not extend our approach to a synthesis of pulvinic acids 32 and 33. While dioxolanone 31 was accessible by a Horner-Wadsworth-Emmons reaction between phosphonate 24b and α-oxo ester 29 (79% yield), it did not react with the ester enolate 30 by Claisen condensation/transesterification (Scheme 5). (Chemical Equation Presented)
-
-
-
|