Diastereoselective Prins-Type Reaction of Cycloalkenylcyclopropanol Silyl Ethers and α,β-Unsaturated Aldehyde Acetals
作者:Ivan L. Lysenko、Heong-Sub Oh、Jin Kun Cha
DOI:10.1021/jo071272o
日期:2007.10.1
Electrophilic addition of 1-(1-cyclohexenyl)-1-cyclopropanol trimethylsilylether to α,β-unsaturated aldehyde acetals under Lewisacidic conditions proceeds with good to excellent diastereoselectivity to afford spirocyclobutanones containing three contiguous stereocenters. A convenient entry to enantioselective syntheses is available by use of a nonracemic C2-symmetric acetal. Elaboration of the resulting
Radical cyclization–fragmentation of ω-haloalkyl cyclobutanones: a modular approach to medium-sized carbocycles
作者:Heong-Sub Oh、Jin Kun Cha
DOI:10.1016/j.tetasy.2003.07.011
日期:2003.10
Kulinkovich cyclopropanation of cycloalkene carboxylates and subsequent electrophilic addition to haloalkyl acetals, provides a convenient method for appending seven- and eight-membered rings onto cycloalkene carboxylates. An enantioselective preparation of a medium-sizedcarbocycle is possible by the use of a non-racemic, C2-symmetric acetal.
Radical Fragmentation of ω-Bromoalkyl Cyclobutanones. A Modular Approach to Eight-Membered Carbocycles
作者:Heong-Sub Oh、Hyoung Ik Lee、Jin Kun Cha
DOI:10.1021/ol026666a
日期:2002.10.1
[reaction: see text] An eight-membered ring was conveniently appended onto a cycloalkene carboxylate by employing a facile radical cyclization-fragmentation reaction of an omega-bromoalkyl spirocyclobutanone, which was readily accessible by the Kulinkovich cyclopropanation and subsequent electrophilic addition to a 3-bromoalkyl acetal.
.alpha.-Substitution-spiroannulation of saturated ketones
作者:Barry M. Trost、Michael K. T. Mao
DOI:10.1021/ja00360a055
日期:1983.10
α-Substitution-spiroannelation de la cyclopentanone. On etudie egalement les reactions de la bicyclo [3.3.0] octene-7one-2
α-取代-螺环退火 de la 环戊酮。研究双环 [3.3.0] octene-7one-2 的反应
Formation of Five-Membered Carbocycles by Intramolecular Palladium-Catalyzed Ring Opening of <i>tert</i>-Cyclobutanols
作者:Manivannan Ethirajan、Heong-Sub Oh、Jin Kun Cha
DOI:10.1021/ol070985q
日期:2007.7.1
We report herein stereoselective formation of a functionalized five-membered carbocycle bearing a quaternary center by intramolecular palladium-catalyzed ring-opening of o-bromophenyl-tethered tert-cyclobutanols.