J. Kawakami et al. / Tetrahedron Letters 47 (2006) 1201–1203
1203
room temperature proceeds regioselectively in good
yield, although 9a and 9b contain two or more different
reactive sites for addition.
(e) Hama, T.; Liu, X.; Culkin, D. A.; Hartwig, J. F. J. Am.
Chem. Soc. 2003, 125, 11176; (f) Awasthi, A. K.; Boys, M.
L.; Cain-Janicki, K. J.; Colson, P.-J.; Doubleday, W. W.;
Duran, J. E.; Farid, P. N. J. Org. Chem. 2005, 70, 5387.
. (a) Nuwa, S.; Handa, S.; Miki, S. US2005043544; (b)
Kawakami, J.; Nakamoto, K.; Nuwa, S.; Handa, S.; Miki,
S. WO2003059889.
8
9
In summary, we have developed a highly selective Refor-
matsky reaction of quinones with crystalline Reformat-
sky reagent 1. The results suggest that the reaction using
crystalline Reformatsky reagent is synthetically very
useful. We are currently examining the application of
this reagent to different classes of substrates.
. Liotta, D.; Saindane, M.; Barnum, C. J. Org. Chem. 1981,
4
6, 3369.
10. Preparation of ethyl(1-hydroxy-4-oxocyclohexa-2,5-dien-
1-yl)acetate (3). Under nitrogen atmosphere, 6 mL of THF
was added to 1.22 g (2 mmol, 0.6 equiv) of (BrZnCH
2
-
CO EtÆTHF) Under argon atmosphere, solution
2
2
.
a
of 0.36 g (3.33 mmol) of p-benzoquinone in 2.5 mL of
THF was added dropwise while stirring at 0–5 ꢁC. The
mixture was stirred at 20–25 ꢁC for 1 h. Five milliliters of
Acknowledgements
We would like to thank Mr. H. Mizutani for the
NOESY spectral analyses of 10a and 10b. We also thank
Mr. K. Yoshida and Dr. K. Tomimatsu for their
encouragement throughout this work.
1
N hydrochloric acid was added dropwise at 20 ꢁC or
lower, followed by dilution with 25 mL of ethyl acetate.
Then, the layers were separated. The organic layer was
washed successively with 5 mL (·2) of 1 N hydrochloric
acid, 5 mL of water, 5 mL (·2) of an aqueous saturated
sodium bicarbonate solution, and 5 mL (·2) of an aqueous
saturated sodium chloride solution. After washing, the
organic layer was dried with anhydrous magnesium
sulfate. After concentration under reduced pressure,
purification with silica gel column (developing solvent;
References and notes
1
2
. Battersby, A. R. In Oxidative Coupling of Phenols; Marcel
Dekker: New York, 1967.
. (a) Forgacs, P.; Provost, J.; Desconclois, J.-F.; Jehanno,
A.; Tiberghien, R.; Touch e´ , A.; Roquet, F.; Godard, F.;
Pesson, M.; Trefou e¨ l, J. C.R. Hebd. Seances Acad. Sci.,
Ser. D 1976, 283, 405; (b) Bohlmann, F.; Knoll, K.-H.
Phytochemistry 1978, 17, 557; (c) Evans, D. A.; Hart, D.
J.; Koelsch, P. M.; Cain, P. A. Pure Appl. Chem. 1979, 51,
ethyl acetate/n-hexane = 1/3, 1/2) afforded 0.46 g of 3
1
(yield 70%).
3
H NMR (300 MHz, CDCl ) d 1.27
(t, J = 7.1 Hz, 3H), 2.70 (s, 2H), 4.19 (q, J = 7.1 Hz, 2
H), 4.36 (s, 1H), 6.17 (d, J = 10.1 Hz, 2H), 6.98 (d,
1
3
J = 10.1 Hz, 2H); C NMR (75 MHz, CDCl
3
) d 14.4,
44.2, 61.8, 67.7, 128.4, 149.9, 170.8, 185.6; IR (NaCl) 3327,
À1
+
1
285; (d) Bohlmann, F.; Zdero, C.; King, R. M.; Robin-
1728, 1668, 1622 cm ; MS (EI), m/z = 196 (M ); Anal.
son, H. Phytochemistry 1981, 20, 2425; (e) Gelbaum, L. T.;
Zalkow, L. H.; Hamilton, D. J. Nat. Prod. 1982, 45, 370;
Calcd for C10
H, 6.00.
12 4
H O : C, 61.22; H, 6.16. Found: C, 60.94;
(
f) Yvin, J. C.; Chevolot, L.; Chevolot-Magueur, A. M.;
11. (a) Evans, D. A.; Hoffman, J. M.; Truesdale, L. K. J. Am.
Chem. Soc. 1973, 95, 5822; (b) Evans, D. A.; Hoffman, J.
M. J. Am. Chem. Soc. 1976, 98, 1983; (c) Evans, D. A.;
Wong, R. Y. J. Org. Chem. 1977, 42, 350; (d) Parker, K.
A.; Andrade, J. R. J. Org. Chem. 1979, 44, 3964.
12. Preparation of ethyl(1-hydroxy-3,5-dimethyl-4-oxocyclo-
hexa-2,5-dien-1-yl)acetate (10a). Under nitrogen atmo-
sphere, 6 mL of THF was added to 1.22 g (2 mmol,
Cochard, J. C. J. Nat. Prod. 1985, 48, 814; (g) Honzumi,
M.; Kamikubo, T.; Ogasawara, K. Synlett 1998, 9, 1001;
(
h) Titulaer, G. T. M.; Zhu, J.; Klunder, A. J. H.;
Zwanenburg, B. Org. Lett. 2000, 2, 473; (i) Shestak, O. P.;
Novikov, V. L.; Ivanova, E. P.; Gorshkova, N. M. Khim.-
Farm. Zh. 2001, 35, 19; (j) Xu, H.; Zhang, N.; Casida, J. E.
J. Agric. Food Chem. 2003, 51, 2544.
3
. (a) Fischer, A.; Henderson, G. N. Tetrahedron Lett. 1980,
0.6 equiv) of (BrZnCH CO EtÆTHF) . Under argon atmo-
2 2 2
2
1, 701; (b) Fischer, A.; Henderson, G. N. Tetrahedron
sphere, a solution of 0.45 g (3.33 mmol) of 2,6-dimethyl-p-
benzoquinone in 3 mL of THF was added dropwise while
stirring at 0–5 ꢁC. The mixture was stirred at 20–25 ꢁC for
1 h. Five milliliters of 1 N hydrochloric acid was added
dropwise at 20 ꢁC or lower, followed by dilution with
25 mL of ethyl acetate. Then, the layers were separated.
The organic layer was washed successively with 5 mL (·2)
of 1 N hydrochloric acid, 5 mL of water, 10 mL (·2) of an
aqueous saturated sodium bicarbonate solution, and 5 mL
(·2) of an aqueous saturated sodium chloride solution.
After washing, the organic layer was dried with anhydrous
magnesium sulfate. After concentration under reduced
pressure, purification with silica gel column (developing
Lett. 1983, 24, 131.
. Araki, S.; Katsumura, N.; Kawasaki, K.; Butsugan, Y.
J. Chem. Soc., Perkin Trans. 1 1991, 499.
. (a) Shriner, R. L. Org. React. 1942, 1, 1; (b) Gaudemar,
M. Organomet. Chem. Rev., A 1972, 8, 183; (c) Rathke, M.
W. Org. React. 1975, 22, 423; (d) F u¨ rstner, A. Synthesis
4
5
1989, 571; (e) F u¨ rstner, A. Angew. Chem., Int. Ed. Engl.
1993, 32, 164; (f) Rieke, R. D. Aldrichim. Acta 2000, 33,
52; (g) Ocampo, R.; Dolbier, W. R., Jr. Tetrahedron 2004,
60, 9325; (h) Orsini, F.; Sello, G. Curr. Org. Synth. 2004, 1,
111.
6
7
. (a) Siegel, A.; Keckeis, H. Monatsh. Chem. 1953, 84, 910;
b) Cornforth, D. A.; Opara, A. E.; Read, G. J. Chem.
(
solvent; ethyl acetate/n-hexane = 1:3) afforded 0.60 g of
1
Soc. C 1969, 2799.
. (a) Orsini, F.; Pelizzoni, F.; Ricca, G. Tetrahedron Lett.
10a (yield 80%). H NMR (300 MHz, CDCl
3
) d 1.28 (t,
J = 7.2 Hz, 3H), 1.89 (s, 6H), 2.64 (s, 2H), 3.87 (s, 1H),
13
1
982, 23, 3945; (b) Orsini, F.; Pelizzoni, F.; Ricca, G.
4.22 (q, J = 7.1 Hz, 2H), 6.68 (s, 2H); C NMR (75 MHz,
Tetrahedron 1984, 40, 2781; (c) Dekker, J.; Boersma, J.;
ven der Kerk, G. J. M. J. Chem. Soc., Chem. Commun.
CDCl
3
) d 13.9, 15.7, 44.0, 61.0, 67.2, 144.2, 144.3, 170.8,
À1
186.3; IR (KBr) 3408, 1732, 1631 cm ; MS (EI), m/z =
224 (M ); Anal. Calcd for C12
Found: C, 64.09; H, 7.28.
+
1
983, 553; (d) Dekker, J.; Budzelaar, P. H. M.; Boersma,
18 4
H O : C, 64.27; H, 7.19.
J.; ven der Kerk, G. J. M. Organometallics 1984, 3, 1403;