Unprecedented regio- and stereoselective conversion of 1-cyclopropyl-3- ethoxycyclopentadienes to 3-(E)-alkylidenecyclopentenes

Bernard L. Flynn, Armin De Meijere

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14 Citations (Scopus)


Cyclopropylalkynes 1 were converted into cyclopropyl-substituted 3- ethoxy-5-dimethylaminocyclopentadienes 4 via initially formed (β- dimethylaminoethenyl)carbene complexes 3 and their subsequent formal [3 + 2] cycloaddition to a second alkyne of type 1 (overall yields 51-59%). New regio- and stereoselective 1,7-addition and 1,6-substitution reactions have been developed that convert cyclopentadienes 4 into highly functionalized cyclopentenes 5 and 11, respectively (yields 98-99% and 61%, respectively). An in situ domino reaction consisting of a [3 + 2] cycloaddition and subsequent 1,7-addition has also been achieved (86% overall yield).

Original languageEnglish
Pages (from-to)400-404
Number of pages5
JournalThe Journal of Organic Chemistry
Issue number2
Publication statusPublished - 22 Jan 1999
Externally publishedYes

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