Ortega Teresa, Ozer Galip, Gronert Scott, Erden Ihsan
San Francisco State University, Department of Chemistry and Biochemistry, 1600 Holloway Avenue, San Francisco, CA 94132, USA.
University of Wisconsin, Wisconsin - Milwaukee, Department of Chemistry and Biochemistry, Cramer St., Milwaukee, WI 53211 USA.
Tetrahedron Lett. 2020 Apr 16;61(16). doi: 10.1016/j.tetlet.2020.151779. Epub 2020 Feb 27.
The singlet oxygenation of three polycyclic hydrocarbons, triquinacene, barrelene and homobarrelene was studied. Triquinacene reacted by way of a perepoxide intermediate, transferring an oxygen atom to another triquinacene molecule to give exclusively the mono epoxide. Barrelene, on the other hand, underwent a rare homo-Diels-Alder reaction with O to give the decomposition product from the initial tetracyclic 1,2-dioxolane leading to benzofuran. The latter reacted with O in a [2+2] cycloaddition to give an unstable 1,2-dioxetane which collapsed to 2-formylphenyl formate. The latter was independently synthesize via singlet oxygenation of authentic benzofuran. Homobarrelene reacted in a similar fashion to give a homoDiels product, decomposition of which led to a keto aldehyde which was characterized spectroscopically. Computational work confirms the barrelene and homobarrelene reactions with O as concerted [2+2+2] cycloadditions.
研究了三种多环烃三蝶烯、桶烯和高桶烯的单重态氧合反应。三蝶烯通过过氧环氧化合物中间体发生反应，将一个氧原子转移到另一个三蝶烯分子上，仅生成单环氧化物。另一方面，桶烯与O发生罕见的同分子狄尔斯-阿尔德反应，从最初的四环1,2-二氧戊环生成分解产物，进而生成苯并呋喃。后者与O发生[2+2]环加成反应，生成不稳定的1,2-二氧杂环丁烷，该二氧杂环丁烷分解生成甲酸2-甲酰基苯基酯。后者通过对纯苯并呋喃进行单重态氧合反应独立合成。高桶烯以类似方式反应生成同分子狄尔斯产物，其分解生成一种酮醛，通过光谱对其进行了表征。计算工作证实桶烯和高桶烯与O的反应为协同的[2+2+2]环加成反应。
