Intramolecular photochemical reactions of 4-(. omega.-alkenyloxy)-6-methyl-2-pyrones having an alkoxycarbonyl group at the olefinic carbon chain

…, J Tajima, T Suishu, K Somekawa

文献索引：Shimo, Tetsuro; Tajima, Jun; Suishu, Takaaki; Somekawa, Kenichi Journal of Organic Chemistry, 1991 , vol. 56, # 25 p. 7150 - 7154

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被引用次数: 10

摘要

Photochemical reactions of 4-(o-alkenyloxy)-6-methyl-2-pyrones 4-8 were investigated. Photosensitized reactions of 2-pyrones 4-6 gave intramolecular [2+ 21 cycloadducts 14-16 ae oxatricyclic lactones, site-, regio-and stereospecifically, but 7 and 8 gave no products. On the other hand, direct irradiations of 4 and 5 afforded cyclobutenecarboxylic acids 19 and 20, respectively. The intramolecular cycloaddition mechanism was also explained from ...