- 作者: 周德璋
- 作者服務機構: Department of Chemistry and Biochemistry, National Chung Cheng University, Chia Yi 621, Taiwan, R.O.C.
- 中文摘要: The Diels-Alder cycloadditions of facially dissymmetric maleic anhydride 1 with facially nonequivalent exocyclic 1,3-butadienes(dimethylidenebicyclo[2.2.2]octene 3 and 2,3,5,6-tetramethylidenebicyclo[2.2.2]-octene (4)) were investigated. In each cycloaddition, the reaction occurred via the course in which 1 added exclusively by its syn-face (same face as the etheno-bridge) onto either p-face of the exocyclic 1,3-butadiene systems to produce only two of the four possible stereoisomeric monocycloadducts (8a/8b and 9a/9b). In the Diels-Alder cycloaddition of 1 with bis-exocyclic butadiene 4, however, both monocycloadducts 9a and 9b underwent subsequent cycloaddition with distinctive facial selectivity to produce the Cs-symmetric bis-cyclohexanobarrelene 10a as only bis-cycloadduct.
- 英文摘要: --
- 中文關鍵字: Diels-Alder cycloaddition; Stereoselectivity; Exocyclic butadiene; Polycyclic compounds.
- 英文關鍵字: Diels-Alder cycloaddition; Stereoselectivity; Exocyclic butadiene; Polycyclic compounds.