| Autor: |
Zimmer, Hans, Amer, Adel, Baumann, Frank M., Haecker, Michael, Hess, Christopher G. M., Ho, Douglas, Huber, Hans J., Koch, Klaus, Mahnke, K., Schumacher, Christian, Wingfield, Robert C. |
| Zdroj: |
European Journal of Organic Chemistry; September 1999, Vol. 1999 Issue: 9 p2419-2428, 10p |
| Abstrakt: |
The synthesis of a number of 8-(dialkylamino)- and 8-alkoxyxanthines (3 and 6, respectively) is described. Treatment of 3 with m-chloroperoxybenzoic acid (m-CPBA) gave by a novel rearrangement 3-(disubstituted amino)-4,7,9-trimethyl-1-oxo-2,4,7,9-tetraazaspiro[4,5]dec-2-ene-6,8,10-triones 10. Also, the corresponding 3-alkoxy-subtituted spiro compounds 12 were obtained by an analogus treatment of 8-alkoxyxanthines 6. In attempts to elucidate a tentative mechanism for this rearrangement 8-[(dialkylamino)methyl]caffeines 7 when treated with m-CPBA did not undergo the rearrangement but only yielded the expected N-oxide derivatives 16. This result seems to indicate that a necessary structure element for this rearrangement to occur is an atom with an unshared pair of electrons to be attached to the 8-position of the investigated xanthines. In agreement with this statement is the fact that N-oxides of 8-[(dialkylamino)methyl]caffeines 16 do not undergo the novel rearrangement but rather give the expected Meisenheimer rearrangement or the Cope elimination depending upon reaction conditions. |
| Databáze: |
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