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Rings with 7 or more membersQ 0050 DOI: 10.1002/chin.201031063

Gold-Catalyzed Intermolecular [4C + 3C] Cycloaddition Reactions. — It is dem-onstrated that Au-catalysts are capable of initiating the reaction of alkynes (I) with cy-clic dienes. The formation of the seven-membered rings occurs by a [4 + 3] cycloaddi-tion, rather than a stepwise cyclopropanation/Cope rearrangement sequence. Cyclopro-panes (IV) can be readily transformed to (III) by Cope rearrangement in toluene under reflux (12h). The seven-membered products represent a central core of the cortistatins. — (GUNG*, B. W.; BAILEY, L. N.; WONSER, J.; Tetrahedron Lett. 51 (2010) 17, 2251-2253, DOI:10.1016/j.tetlet.2010.02.099; Dep. Chem. Biochem., Miami Univ., Oxford, OH 45056, USA; Eng.) — Mais

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