Thermal Addition Reaction of Aroylketene with 1-Aryl-1-trimethylsilyloxyethylenes: Aromatic Substituent Effects of Aroylketene and Aryltrimethylsilyloxyethylene on Their Reactivity.
Brønsted acid catalyzed tandem cyclization was found to be highly effective for the preparation of a series of polysubstituted 4-pyrones from diynones (yield up to 99%). 4-Pyridone and 3-pyrrolone derivatives were also selectively synthesized by employing NIS and/or Brønsted acid. NIS as an electrophilic reagent could promote these reactions efficiently and rapidly under very mild reaction conditions
New Strong Base Synthesis of Symmetrical 1,5-Diaryl-1,3,5-pentanetriones from Acetone and Benzoate Esters
作者:John D. Knight、Clyde R. Metz、Charles F. Beam、William T. Pennington、Donald G. VanDerveer
DOI:10.1080/00397910802138488
日期:2008.6.27
Lithium hexamethyldisilazide (LiHMDS) was used to condense substituted benzoate esters with acetone to afford symmetrical 1,5-diaryl-1,3,5-pentanetriones that were isolated, characterized (including a representative X-ray crystallographic analysis), and acid cyclized to the respective 2,6-diaryl-4H-pyran-4-ones.