5-Exo cyclizations of primary and secondary radicals with acylsilanes successfully give cyclopentyl silyl ethers. The corresponding 6-exo cyclizations are sensitive to changes of the size of silyl groups. Secondary radicals undergo 6-exo cyclizations with acylsilanes more slowly. Reaction of aryl radical with acylsilane proceeds well for 5-exo cyclization but not for 6-exo cyclization. Vinyl radicals give best results in 5-exo cyclizations with acylsilanes but give low yields (similar to 30%) in 6-exo cyclizations. Intramolecular cyclizations of vinyl radicals with acylsilanes give enol silyl ethers regiospecifically.
Paul, Comptes Rendus Hebdomadaires des Seances de l'Academie des Sciences, 1931, vol. 193, p. 599
作者:Paul
DOI:——
日期:——
SHI, L.;NARULA, C. K.;MAK, K. T.;KAO, L.;XU, Y.;HECK, R. F., J. ORG. CHEM., 1983, 48, N 22, 3894-3900
作者:SHI, L.、NARULA, C. K.、MAK, K. T.、KAO, L.、XU, Y.、HECK, R. F.
DOI:——
日期:——
Vinylcyclobutanols: A Composite Functional Group?
作者:Barry M. Trost、Deborah W. C. Chen
DOI:10.1021/ja9624432
日期:1996.1.1
probed by the examination of the behavior of vinylcyclobutanols as terminators in cyclization reactions. The substrates were readily available by the addition of vinyllithium reagents bearing acetals as cyclization initiators to cyclobutanone. Bronsted and Lewis acids both promoted cyclization in contrast to vinylcyclopropanolterminators for which Bronsted acids failed. The products are spirocycles consisting