Stereoselective Synthesis of (E)-2-En-4-ynoic Acids with Ynolates: Catalytic Conversion to Tetronic Acids and 2-Pyrones
摘要:
A highly torquoselective olefination of alkynoates to provide functionalized tetrasubstituted olefins, (E)-2-en-4-ynoic acids, is described. Addition of Bronsted acids dramatically switched the mode of the Ag(l)-catalyzed cyclization of the resulting enyne carboxylic acids to give either tetronic acids or 2-pyrones.
Stereoselective Synthesis of (E)-2-En-4-ynoic Acids with Ynolates: Catalytic Conversion to Tetronic Acids and 2-Pyrones
摘要:
A highly torquoselective olefination of alkynoates to provide functionalized tetrasubstituted olefins, (E)-2-en-4-ynoic acids, is described. Addition of Bronsted acids dramatically switched the mode of the Ag(l)-catalyzed cyclization of the resulting enyne carboxylic acids to give either tetronic acids or 2-pyrones.