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HETEROCYCLES, Vol. 70, 2006
reaction conditions using 10 (71.7 mg) to provide 45.6 mg (19%) of 11 and 159 mg of 9 was
recovered. The recovered 9 (159 mg) was subjected to the same reaction conditions using 10 (52.8
mg) to provide 24.9 mg (16%) of 11 and 112 mg of 9 was recovered. Again the recovered 9 (112
mg) was subjected to the same reaction conditions using 10 (26.4 mg) to provide 12.8 mg (11%) of
11 and 67.2 mg of 9 was recovered. After the three recycles, totally 139 mg (27%) of 11 was
obtained from 516 mg of 9. Compound (11): TLC Rf 0.31 (EtOAc/hexane, 1:2); IR (neat) 2920,
1750 cm-1; 1H NMR (270 MHz, CDCl3) δ 2.32-2.50 (m, 4H), 3.69 (s, 3H), 3.86 (s, 3H), 5.02 (dt, 1H,
J = 11.4, 1.8 Hz), 5.08 (dt, 1H, J = 17.0, 1.8 Hz), 5.85 (ddt, 1H, J = 11.4, 17.0, 6.2 Hz), 6.63 (m, 1H),
6.81 (d, 1H, J = 9.2 Hz), 6.89 (d, 1H, J = 9.2 Hz), 7.02 (m, 1H);13C NMR (68 MHz, CDCl3) δ 24.5,
31.3, 56.5, 56.9, 80.4, 111.4, 112.9, 115.1, 115.5, 122.6, 133.6, 137.0, 145.9, 150.4, 153.5, 174.6;
HRMS calcd for C16H17O4Br (M+) m/z 352.0310, found 352.0309.
14. For reports on metathesis applying to cyclobutene derivatives: (a) M. Mori, H. Wakamatsu, K.
Tonogaki, R. Fujita, T. Kitamura, and Y. Sato, J. Org. Chem., 2005, 70, 1066. (b) M. L. Randall, J.
A. Tallarico, and M. L. Snapper, J. Am. Chem. Soc., 1995, 117, 9610.
15. Y. Naruta, Y. Nishigaichi, and K. Maruyama, Org. Synth., 1993, 71, 118.
16. Compound (13) was obtained as a colorless oil: TLC Rf 0.65 (EtOAc/hexane, 1:2); IR 2940, 1750
cm-1; 1H NMR δ 1.79 (s, 3H), 2.34-2.52 (m, 4H), 3.37 (d, 1H, J = 16.9 Hz), 3.55 (d, 1H, J = 16.9 Hz),
3.65 (s, 3H), 3.76 (s, 3H), 4.30 (s, 1H), 4.77 (s, 1H), 4.99-5.11 (m, 2H), 5.84 (m, 1H), 6.08 (br s, 1H),
6.72 (d, 1H, J = 9.0 Hz), 6.86 (d, 1H, J = 9.0 Hz), 6.98 (br s, 1H); 13C NMR δ 17.9, 23.2, 31.5, 33.3,
56.1, 56.5, 78.1, 110.5, 110.7, 112.3, 126.0, 127.0, 128.0, 137.3, 144.8, 147.7, 147.8, 151.9, 153.3,
174.8; HRMS (EI) calcd for C20H24O4 (M+) m/z 328.1675, found 328.1675.
17. (a) A. F. Littke and G. C. Fu, Angew. Chem. Int. Ed. Engl., 1999, 38, 2411. (b) A. F. Littke, L.
Schwarz, and G. C. Fu, J. Am. Chem. Soc., 2002, 124, 6343.
18. M. Scholl, S. Ding, C. W. Lee, and R. H. Grubbs, Org. Lett., 1999, 1, 953.
19. S. B. Garber, J. S. Kingsbury, B. L. Gray, and A. H. Hoveyda, J. Am. Chem. Soc., 2000, 122, 8168.
20. Compound 16 was obtained as amorphous solid:1H NMR δ 2.52 (s, 3H), 3.94 (s, 3H), 3.95 (s, 3H),
6.62 (d, 1H, J = 8.1 Hz), 6.67 (d, 1H, J = 8.1 Hz), 7.33 (d, 1H, J = 8.4 Hz), 7.98 (s, 1H), 8.09 (d, 1H,
13
J = 8.4 Hz): C NMR δ 21.8, 55.6, 55.7, 102.2, 103.3, 120.8, 121.7, 124.5, 126.4, 127.9, 135.6,
149.0, 149.6. These data were identical with those reported for 16 in the following paper: B. K.
Mehta, O. Barun, H. Ila, and H. Junjappa, Synthesis, 1998, 1483.
21. An analogous intermolecular Pd(0)-catalyzed allylation of aromatic rings, see: B. Nay, J.-F. Peyrat,
and J. Vercauteren, Eur. J. Org. Chem. 1999, 2231.
22. Synthesis of 21: To a stirred solution of 19 (12.6 mg, 45.9 µmol) in benzene (4.6 mL) were added
methallyl acetate (56 µL, 460 µmol) and a solution of the Grubbs catalyst (15) (11.7 mg, 4.6 µmol)