The reaction of photochemically generated α-hydroxyalkyl radicals with alkynes: a synthetic route to γ-butenolides
作者:Niall W.A. Geraghty、Elaine M. Hernon
DOI:10.1016/j.tetlet.2008.11.067
日期:2009.2
and their subsequent carbon-carbon bond forming reaction with propiolate esters and acetylenedicarboxylates, gives a mixture of a β-(hydroxyalkyl)enoate, the result of a formal cis addition, and the unsaturated lactone (γ-butenolide) resulting from the spontaneous cyclization of the corresponding trans addition product. Treatment of the cis adduct with NBS converts it to the same lactone, and so the
Bromine-Induced Facile Synthesis of Butenolides and Spirobutenolides from Sterically Congested Tetrasubstituted Dialkyl Alkylidene Succinates
作者:Narshinha Argade、Ramesh Patel
DOI:10.1055/s-0029-1219233
日期:2010.4
Starting from sterically congested tetrasubstituted dialkyl alkylidene succinates, facile general approach to several dialkyl substituted butenolides and spirobutenolides with the generation of quaternary carbon center has been demonstrated via bromine-induced dealkylative regioselective intramolecular cyclization and dehydrobromination pathway. The mechanistic aspects involved in the formation of butenolides have been also described in brief.