A novel microwave-assisted, highly efficient protocol for the synthesis of hitherto unknown aza-analogues of (-)-Steganacin, a naturally occurring bisbenzocyclooctadiene lignan lactone with potent antileukemic and tubulin polymerization inhibitory activity, has been developed. Focused microwave irradiation is demonstrated to be highly beneficial in promoting the three crucial steps of the sequence to effect the final ring closure: the Suzuki-Miyaura reaction, Cu-mediated A3-coupling, as well as the intramolecular Huisgen 1,3-dipolar cycloaddition.

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Alkaloids U 0600Diversity Oriented Microwave-Assisted Synthesis of (-)-Steganacin Aza-Analogues. -(MONT, N.; MEHTA, V. P.; APPUKKUTTAN, P.; BERYOZKINA, T.; TOPPET, S.; VAN HECKE, K.; VAN MEERVELT, L.; VOET, A.; DEMAEYER, M.; VAN DER EYCKEN*, E.; J. Org. Chem. 73 (2008) 19, 7509-7516; Lab. Org. Microwave-Assisted Chem., Dep. Chem., Univ. Leuven, B-3001 Leuven, Belg.; Eng.) -Jannicke 08-198

Rearrangements of 1-Phenyl-1,2,3-triazoles Bearing a Hydrazone or Oxime Function at the 4-Position. --(L'ABBE, G.; VAN ESSCHE, G.; DELBEKE, P.; TOPPET, S.; Bull. Soc. Chim. Belg. 99 (1990) 10, 833-834; Dep. Chem., Univ. Leuven, 3030 Heverlee, Belg.; EN)

Synthesis of Novel Isothiazole and Isothiazolo(4,pyrimidine Analogues of the Natural C-Nucleosides Pyrazofurin and the Formycins. -The title compounds (I)-(III) are evaluated for their antiviral and antitumor activity. Despite their structural similarities to pyrazofurin and formycin they do not exhibit activity. -(BUFFEL, D. K.; MEERPOEL, L.; TOPPET, S. M.; HOORNAERT, G. J.; Nucleosides Nucleotides 13 (1994) 1-3, 719-736; Dep. Scheikd., Lab. Org. Synth., Kathol. Univ. Leuven, B-3001 Heverlee-Leuven, Belg.; EN)