4-Hydroxybenzaldehyde O-(2-oxo-2H-chromen-7-yl) oxime 17
using a Cytofluor II Fluorescence Plate Reader (Perseptive
Biosystems, filters λex = 360 20, λem = 460 20 nm), or of
polystyrene 96-well-plates (Costar) using a Spectramax 250
Microplate Spectrophotometer (Molecular Devices).
Application of the procedure above starting from umbelliferone
8 (100 mg, 0.62 mmol) and 4-hydroxybenzaldehyde (75 mg, 0.62
mmol) followed by flash chromatography purification (3 : 2
hexane : ethyl acetate) gave 17 (80 mg, 46%) as a white solid.
1
Mp: 122 ЊC; H NMR (400 MHz, DMSO-d6): δ = 10.27 (br s,
Acknowledgements
1 H), 8.78 (s, 1 H), 8.17 (d, 1 H, J = 9.5 Hz), 7.85–7.81 (m, 3 H),
7.41 (d, 1 H, J = 2.3 Hz), 7.32 (dd, 1 H, J = 8.8, 2.3 Hz), 7.01 (d,
2 H, J = 8.8 Hz), 6.48 (d, 1 H, J = 9.5 Hz); 13C NMR (100 MHz,
DMSO-d6): δ = 162.2, 160.8, 160.5, 155.5, 154.2, 144.6, 130.2,
130.1, 121.5, 116.3, 113.8, 113.5, 111.5, 101.5; ESI-HRMS:
calcd. for C16H12NO4 [M ϩ H]ϩ: 282.0766; found: 282.0762.
This work was supported by the Swiss National Science Found-
ation, the Swiss Office Fédéral de l’Education et de la Science,
and Protéus SA, Nîmes, France.
References
4-Methyl-7-[(methyleneamino)oxy]-2H-chromen-2-one 18
1 (a) Enzyme Assays: A Practical Approach, eds. Robert Eisenthal and
Michael Danson, Oxford University Press, 2002; (b) S. Gul, S. K.
Sreedharan and K. Brocklehurst, Enzyme Assays: Essential Data,
John Wiley & Sons, 1998; (c) M. T. Reetz, Angew. Chem., Int. Ed.,
2001, 40, 284; (d ) D. Wahler and J.-L. Reymond, Curr. Opin. Chem.
Biol., 2001, 5, 152; (e) F. Beisson, A. Tiss, C. Rivière and R. Verger,
Eur. J. Lipid Sci. Technol., 2000, 133; ( f ) D. Wahler and
J.-L. Reymond, Curr. Opin. Biotechnol., 2001, 12, 535.
2 (a) L. E. Janes and R. J. Kazlauskas, J. Org. Chem., 1997, 62, 4560;
(b) L. E. Janes, A. C. Löwendahl and R. J. Kazlauskas, Chem. Eur.
J., 1998, 4, 2324.
3 (a) G. Klein, D. Kaufmann, S. Schürch and J.-L. Reymond,
Chem. Commun., 2001, 561; (b) G. Klein and J.-L. Reymond,
Angew. Chem., Int. Ed., 2001, 40, 1771; (c) K. E. S. Dean, G. Klein,
O. Renaudet and J.-L. Reymond, Bioorg. Med. Chem. Lett., 2003,
10, 1653.
Application of the procedure above starting from 4-methyl-
umbelliferone 9 (200 mg, 1.13 mmol) and an aqueous solu-
tion of formaldehyde (30 mg, 1.13 mmol) followed by flash
chromatography purification (3 : 2 hexane : ethyl acetate)
gave 18 (115 mg, 50%) as a white solid. Mp: 98–99 ЊC; 1H NMR
(300 MHz, DMSO-d6): δ = 7.75 (d, 1 H, J = 8.7 Hz), 7.63 (d,
1 H, J = 5.6 Hz), 7.27 (d, 1 H, J = 5.6 Hz), 7.17–7.11 (m, 2 H),
6.27 (q, 1 H, J = 1.2 Hz), 2.42 (d, 3 H, J = 1.2 Hz); 13C NMR (75
MHz, DMSO-d6): δ = 161.2, 159.9, 154.3, 144.9, 126.8, 114.6,
112.8, 111.9, 110.7, 102.1, 101.2, 18.1; EI-HRMS: calcd. for
C11H9NO3 [M]ϩ: 203.058243; found: 203.058070.
Benzaldehyde O-(4-methyl-2-oxo-2H-chromen-7-yl) oxime 19
4 (a) D. Wahler and J.-L. Reymond, Angew. Chem., Int. Ed., 2002, 41,
1229; (b) Y. Yang, D. Wahler and J.-L. Reymond, Helv. Chim. Acta,
2003, 86, 2928.
5 E. Henke and U. T. Bornscheuer, Anal. Chem., 2003, 75, 255.
6 M. Konarzycka-Bessler and U. T. Bornscheuer, Angew. Chem.,
Int. Ed., 2003, 42, 1418.
7 (a) N. Bensel, M. T. Reymond and J.-L. Reymond, Chem. Eur. J.,
2001, 7, 4604; (b) E. Leroy, N. Bensel and J.-L. Reymond, Bioorg.
Med. Chem. Lett., 2003, 13, 2105.
8 J.-L. Reymond, T. Koch, J. Schröer and E. Tierney, Proc. Natl. Acad.
Sci. USA, 1996, 93, 4251.
9 (a) K. Rose, J. Am. Chem. Soc., 1994, 116, 30; (b) L. E. Canne, A. R.
Ferré-D’Amaré, S. K. Burley and S. B. H. Kent, J. Am. Chem. Soc.,
1995, 117, 2998; (c) J. Shao and J. P. Tam, J. Am. Chem. Soc., 1995,
117, 3893; (d ) E. C. Rodriguez, K. A. Winans, D. S. King and C. R.
Bertozzi, J. Am. Chem. Soc., 1997, 119, 9905; (e) S. E. Cervigni,
P. Dumy and M. Mutter, Angew. Chem., Int. Ed., 1996, 35, 1230;
( f ) O. Renaudet and P. Dumy, Org. Lett., 2003, 5, 243; (g) D. Forget,
D. Boturyn, E. Defrancq, J. Lhomme and P. Dumy, Chem. Eur. J.,
2001, 7, 3976; (h) L. K. Mahal, K. J. Yarema and C. R. Bertozzi,
Science, 1997, 276, 1125; (i) K. J. Yarema, L. K. Mahal, R. E.
Bruehl, E. C. Rodriguez and C. R. Bertozzi, J. Biol. Chem., 1998,
273, 31168.
Application of the procedure above starting from 4-methyl-
umbelliferone 9 (100 mg, 0.57 mmol) and benzaldehyde (60 mg,
0.57 mmol) followed by flash chromatography purification (3 : 2
hexane : ethyl acetate) gave 19 (70 mg, 44%) as a white solid.
Mp: 122 ЊC; 1H NMR (400 MHz, DMSO-d6): δ = 8.93 (s, 1 H),
7.98 (dd, 2 H, J = 8.0, 2.1 Hz), 7.90 (d, 1 H, J = 8.8 Hz), 7.68–
7.63 (m, 3 H), 7.44–7.43 (m, 1 H), 7.37 (dd, 1 H, J = 8.8, 2.1 Hz),
6.41 (s, 1 H), 2.57 (s, 3 H); 13C NMR (100 MHz, DMSO-d6):
δ = 161.8, 160.3, 154.8, 154.4, 153.6, 131.7, 130.9, 129.4, 128.3,
127.1, 114.9, 112.2, 111.2, 101.7, 18.5; EI-HRMS: calcd. for
C17H13NO3 [M]ϩ: 279.089543; found: 279.089290.
2-Nitrobenzaldehyde O-(4-methyl-2-oxo-2H-chromen-7-yl)
oxime 20
Application of the procedure above starting from 4-methyl-
umbelliferone 9 (200 mg, 1.13 mmol) and 2-nitrobenzaldehyde
(170 mg, 1.13 mmol) followed by flash chromatography purifi-
cation (3 : 2 hexane : ethyl acetate) gave 20 (115 mg, 31%) as a
1
yellow solid. Mp: 153–154 ЊC; H NMR (300 MHz, CDCl3):
10 O. Renaudet and J.-L. Reymond, Org. Lett., 2003, 5, 4693.
11 (a) Y. Endo, K. Shudo and T. Okamoto, Synthesis, 1980, 6, 61;
(b) Y. Tamura, J. Minamikawa and M. Ikeda, Synthesis, 1977, 1.
12 (a) J. Hine, B. C. Menon, J. H. Jensen and J. Mulders, J. Am. Chem.
Soc., 1966, 88, 3367; (b) J.-L. Reymond and Y. Chen, J. Org. Chem.,
1995, 60, 6970.
δ = 9.09 (s, 1 H), 8.19 (dd, 1 H, J = 8.1, 1.5 Hz), 8.13 (d, 1 H,
J = 7.7, 1.5 Hz), 7.79 (td, 1 H, J = 7.7, 1.5 Hz), 7.70 (td, 1 H,
J = 8.1, 1.5 Hz), 7.59 (d, 1 H, J = 8.8 Hz), 7.35 (d, 1 H,
J = 2.5 Hz), 7.17 (dd, 1 H, J = 8.8, 2.5 Hz), 6.22 (s, 1 H), 2.46 (s,
3 H); 13C NMR (75 MHz, DMSO-d6): δ = 163.8, 162.7, 157.1,
156.0, 154.4, 150.7, 146.3, 136.9, 134.8, 132.6, 129.6, 127.8,
127.6, 114.8, 113.6, 104.3, 20.7; ESI-HRMS: calcd. for C17H13-
N2O5 [M ϩ H]ϩ: 325.0824; found: 325.0824.
13 R. Nguyen and I. Huc, Chem. Commun., 2003, 942.
14 (a) M. Miller and G. Loudon, J. Org. Chem., 1975, 40, 126;
(b) G. Sosnovsky, J. A. Krogh and S. G. Umhoefer, Synthesis,
1979, 722; (c) G. A. Olah and T. Keumi, Synthesis, 1979, 112;
(d ) J. Liebscher and H. Hartmann, Z. Chem., 1975, 15, 302.
15 (a) D. S. Kemp and R. B. Woodward, Tetrahedron, 1965, 21, 3019;
(b) F. Hollfelder, A. J. Kirby, D. S. Tawfik, K. Kikuchi and
D. Hilvert, J. Am. Chem. Soc., 2000, 122, 1022; (c) F. Hollfelder,
A. J. Kirby and D. S. Tawfik, Nature, 1996, 60, 383; (d ) K. Kikuchi,
S. N. Thorn and D. Hilvert, J. Am. Chem. Soc., 1996, 118, 8184.
Kinetic measurements
All substrates were diluted from stock solutions in 50% DMF,
and stored at ϩ4 ЊC. Assays (0.1 ml) were followed in individual
wells of round-bottom polypropylene 96-well-plates (Costar)
O r g . B i o m o l . C h e m . , 2 0 0 4 , 2, 1 4 7 1 – 1 4 7 5
1475