intramolecular Diels-Alder cyclization. Compounds 6 and 10 rearrange by treatment with boron trifluoride-diethyl ether to the isomeric compounds 7 and 11. The structures 6f and 7f were confirmed by X-ray analysis. Condensation of the 3,5-diaryl-1,2,4-dithiazolium salts 3 with the metal cyclopentadienides 4 affords the tricyclic compounds 12, which do not rearrange by Lewis acid catalysis.
3,5-二芳基-1,2-二
硫鎓盐2与
金属
环戊二烯化物4和9的反应通过开环中间体形成
三环化合物6和10,该中间体经历分子内Diels-Alder环化反应。通过用
三氟化硼-
乙醚处理,化合物6和10重排为异构体化合物7和11。通过X射线分析确认了结构6f和7f。3,5-二芳基-1,2,4-二
噻唑鎓盐3与
金属
环戊二烯化物4的缩合得到
三环化合物12,其不通过
路易斯酸催化重排。