Synthesis of Isocoumarins and α-Pyrones via Electrophilic Cyclization
作者:Tuanli Yao、Richard C. Larock
DOI:10.1021/jo034308v
日期:2003.7.1
A variety of substituted isocoumarins and alpha-pyrones are readily prepared in excellent yields under very mild reaction conditions by the reaction of o-(1-alkynyl)benzoates and (Z)-2-alken-4-ynoates with ICI, I-2, PhSeCl, p-O2NC6H4SCl, and HI. This methodology accommodates various alkynyl esters and has been successfully extended to the synthesis of polycyclic aromatic and biaryl compounds.
Regioselective Synthesis of 5-Metalated 2-Pyrones by Intramolecular Oxymetalation of Carbonyl-ene-yne Compounds Using Indium Trihalide
The oxyindation of carbonyl-ene-yne compounds with indium trihalides proceeded efficiently to give di-, tri-, and tetrasubstituted 2-pyrones bearing a carbon-indium bond. The metalated 2-pyrone and a zwitterion intermediate were identified by X-ray crystallographic analysis. The application of organoindium compounds to oxidation or cross-coupling provided easy access to various multifunctionalized