| Autor: |
Hiromichi Akizawa, Mikiko Kudo, Koh-ichi Seki, Tetsuya Ishihara, Nobuhiro Oshima, Kazue Ohkura |
| Jazyk: |
angličtina |
| Rok vydání: |
2012 |
| Předmět: |
|
| Zdroj: |
Heterocycles. 84(2):1057-1065 |
| ISSN: |
0385-5414 |
| Popis: |
Direct UV-irradiation of 5-fluoro-1,3-dimethyluracil (5-FDMU) and naphthalene (1) with a 500 W high-pressure mercury lamp in a degassed Pyrex tube (λ > 300 nm) predominantly afforded benzopyrimidobarrelene derivative (2) through 1,4-addition, while irradiation in the presence of piperylene in singlet excited states preferentially afforded naphthocyclobuta-pyrimidine derivative (3) via 1,2-addition. Upon 254 nm light-irradiation of 2 gave rise to the formation of benzopyrimidosemibullvalene (4) in fair yields. The reaction pathway for the formation of 4 is reasonably explained in the terms of di-π-methane rearrangement. Adduct 3 was newly converted to the corresponding barrelene derivative (2) by long-wave-length irradiation in the presence of a triplet sensitizer. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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