Intramolecular reductive cyclization of unsaturated keto- or aldo-esters by samarium(<scp>II</scp>) di-iodide: a ready synthesis of bicyclic γ-lactones
Treatment of unsaturatedketo- or aldo-esters with Sml2 in tetrahydrofuran (THF) or THF–hexamethylphosphoramide affords bicyclicγ-lactones in moderate to good yields.
Intramolecular Michael reactions of aliphatic aldehyde enolates generated by imidazolium carbenes
作者:Hyoungsu Kim、Seong Rim Byeon、Marina G.D. Leed、Jiyong Hong
DOI:10.1016/j.tetlet.2011.03.008
日期:2011.5
conditions required for the direct generation of aldehyde enolates, intramolecular Michaeladditions of aldehyde enolates to α,β-unsaturated carbonyl compounds have been underexplored for the stereoselective synthesis of carbocyclic compounds. The intramolecular Michael reaction of aldehyde enolates generated by imidazolium carbenes was explored for the synthesis of cyclopentane aldehydes. The imidazolium carbenes