69184-79-8Relevant articles and documents
THE MUKAIYAMA REACTION OF KETENE BIS(TRIMETHYLSILYL)ACETALS WITH α-HALO ACETALS - A CONVENIENT BUTENOLIDE SYNTHESIS
Demnitz, F. W. J.
, p. 6109 - 6112 (1989)
Ketene bis(trimethylsilyl) acetals were reacted with α-halo acetals giving β-alkoxy-γ-halo acids which were converted to butenolides by reaction with equivalents of base.This constitutes a novel and short butenolide synthesis.
Diastereoselective cyclopropanation of ketone enols with Fischer carbene complexes
Barluenga, Jose,Suero, Marcos G.,Perez-Sanchez, Ivan,Florez, Josefa
, p. 2708 - 2709 (2008)
Treatment of aryl/heteroaryl methoxycarbene complexes of chromium with β-substituted ketone lithium enolates between -78 °C and room temperature resulted in the diastereoselective synthesis of 1,2,2,3-tetrasubstituted cyclopropanols. An exception has been observed in the reaction with cyclohexanone lithium enolate that yielded a bicyclic 2-buten-4-olide. 1,2-Dimethoxycyclopropanes and 1-methoxy-2-trimethylsilyloxycyclopropanes were isolated by quenching the reactions with MeOTf or Me3SiCl, respectively. This novel cyclopropanation process involves formation of lithium (3-oxoalkyl)pentacarbonylchromate intermediates which on warming undergo intramolecular addition to the carbonyl group. This cyclization is equivalent to the cyclopropanation in smooth conditions of electron-rich alkenes with Fischer carbene complexes. Copyright