1,4-Diazabicyclo[2.2.2]octane (DABCO)-catalysed Baylis-Hillman reactions of selected chromone-3-carbaldehydes with methyl acrylate have been shown to afford mixtures of the expected Baylis-Hillman products and unprecedented dimeric derivatives. The Baylis–Hillman products, on heating at 80°C in the presence of DABCO, are converted to the corresponding dimers, the structures of which have been unambiguously established by NMR and X-ray crystallographic analysis. Electron-impact and electrospray MS data for the dimeric systems are discussed.
Part 13. GrayC.A., KayeP. T., and NchindaA. T., paper submitted to J. Nat. Prod.
2.
MartinezJ., SilvánA. M., AbadM. J., BermejoP., VillarA., and SöllhuberM., J. Nat. Prod., 1997, 60, 142.
3.
GerwickW.H., LopezA., Van DuyneG. D., ClardyJ., OrtizW., and BaezA., Tetrahedron Lett., 1996, 27, 1979.
4.
DavidsonD.N., KayeP. T., and RamaiteI. D. I., J. Chem. Res., 1993, 462.
5.
KayeP.T., NchindaA. T., SabbaghL. V., and McClelandC. W., J. Chem. Res., 2000, 237.
6.
DavidsonD.N., and KayeP. T., J. Chem. Soc. Perkin Trans. 2, 1991, 1509.
7.
For a recent review of the (Morita-) Baylis-Hillman reaction see CiganekE., Org. React. (N.Y.), 1997, 51, 201.
8.
See, for example, KayeP.T., and NocandaX. N., Synthesis, 2001, 2389.
9.
MillerD., WangS., ReidJ., XieW., GauvinB., KelleyM., SarupJ., SawutzD. G., MiskiM., DolleR. E., and FaltynekC. R., Drug Dev. Res., 1995, 34, 344.
10.
GhoshC.K., and KhanS., Synthesis, 1980, 701; S. T. Saengchantara and T. W. Wallace, J. Chem. Soc., Perkin Trans. 1, 1986, 789; P. J. Cremins and T. W. Wallace, J. Chem. Soc., Chem. Commun., 1984, 1698.
11.
EidenF., and HaverlandH., Arch. Pharm., 1967, 300, 806; G. J. P. Becket, G. W. Ellis, M. I. U. Trindade and U. Iolanda, J. Chem. Res. (S), 1978, 47; S. Klutchko, M. P. Cohen, J. Sharel, Jr., and M. von Strandtmann, J. Heterocycl. Chem., 1974, 11, 183.
12.
NoharaA., UmetaniT., and SannoY., Tetrahedron Lett., 1973, 1995; A. Nohara, T. Umetani and Y. Sanno, Tetrahedron, 1974, 30, 3553.
13.
BandyopadhyayC., SurK. R., and PatraR., J. Chem. Res. (S), 1998, 802; C. Bandyopadhyay, K. R. Sur and H. K. Das, J. Chem. Res. (S), 1999, 598.
14.
Al-MaharikN.I., KaltiaS. A. A., MutikainenI., and WähäläK., J. Org. Chem., 2000, 65, 2305.
