Cascade Reactions of β??Amino??Substituted α, β??Unsaturated Fischer Carbene Complexes with 1, 5??Dien??3??ynes as a Convenient Access to Ring??Annelated …

…, M Noltemeyer, A de Meijere

Index: Wu, Yao-Ting; Noltemeyer, Mathias; De Meijere, Armin European Journal of Organic Chemistry, 2005 , # 13 p. 2802 - 2810

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Citation Number: 7

Abstract

Abstract Upon heating pentacarbonyl (3-dimethylamino-1-ethoxypropenylidene) chromium complexes 1 with 1, 5-dien-3-ynes 2 in pyridine at 80 C, benzene-annelated cyclopentenones 8 and their regioisomers 9, resulting from a sequence of cocyclization, 6π- electrocyclization and hydrolysis, were isolated in 12–75% yield (13 examples). The more flexible the alkenyl substituents were in the dienynes 2, the longer were the reaction times ...