Unprecedented Regio- and Stereoselective Conversion of 1-Cyclopropyl-3-ethoxycyclopentadienes to 3-(E)-Alkylidenecyclopentenes

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 stereose...

Full description

Saved in:
Bibliographic Details
Published in:Journal of organic chemistry 1999-01, Vol.64 (2), p.400-404
Main Authors: Flynn, Bernard L, de Meijere, Armin
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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).
ISSN:0022-3263
1520-6904
DOI:10.1021/jo980938z