Synthesis of isocoumarins and alpha-pyrones via tandem Stille reaction/heterocyclization.
A general route to alpha-pyrones and 3-substituted isocoumarins from (Z)-iodovinylic acids 1a-f or 2-iodobenzoic acids 4a-c is described, including compounds bearing a substituent on the aromatic ring. Treatment of (Z)-beta-iodovinylic acids 1a-f or 2-iodobenzoic acids 4a-c with various allenyltributyltin reagents in the presence of palladium acetate, triphenylphosphine, and tetrabutylammonium bromide in dimethylformamide provided good yields of the corresponding alpha-pyrones 3a-k or 3-substituted isocoumarins 5a-g via tandem Stille reaction and 6-endo-dig oxacyclization.
Cherry
Khalil
K
Laboratoire de Synthèse et Physico-Chimie Organique et Thérapeutique, Faculté des Sciences de Tours, Parc de Grandmont, EA 3857, 37200 Tours, France.
Parrain
Jean-Luc
JL
Thibonnet
Jérôme
J
Duchêne
Alain
A
Abarbri
Mohamed
M
D003500:Cyclization; D049934:Isocoumarins / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D011753:Pyrones / Q000138:chemical synthesis*; D021241:Spectrometry, Mass, Electrospray Ionization
D049934:Isocoumarins; D011753:Pyrones