I2–PPh3 mediated spiroannulation of unsaturated β-dicarbonyl compounds. The first synthesis of (±)-negundoin A
作者:Rubén Tapia、Ma José Cano、Hanane Bouanou、Esteban Alvarez、Ramón Alvarez-Manzaneda、Rachid Chahboun、Enrique Alvarez-Manzaneda
DOI:10.1039/c3cc45921g
日期:——
An efficient and stereoselective spiroannulation of unsaturated enols is reported. Unsaturated beta-dicarbonyl compounds undergo cyclization by reaction with catalytic I2-PPh3, affording the corresponding spiro enol ether derivatives, with complete regio- and stereoselectivity, under mild conditions. Utilizing this new methodology, the first total synthesis of the anti-inflammatory diterpene negundoin