I2-PPh3 mediated spiroannulation of unsaturated β-dicarbonyl compounds. The first synthesis of (±)-negundoin A.
An efficient and stereoselective spiroannulation of unsaturated enols is reported. Unsaturated β-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 A and a naturally occurring trypanocidal aldehyde is reported.
Departamento de Química Orgánica, Facultad de Ciencias, Instituto de Biotecnología, Universidad de Granada, 18071 Granada, Spain. eamr@ugr.es rachid@ugr.es.
Rubén
R
Tapia
Ma José
MJ
Cano
Hanane
H
Bouanou
Esteban
E
Alvarez
Ramón
R
Alvarez-Manzaneda
Rachid
R
Chahboun
Enrique
E
Alvarez-Manzaneda
D002384:Catalysis; D003500:Cyclization; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D007455:Iodine / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry*; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry
D004224:Diterpenes; D007659:Ketones; D009943:Organophosphorus Compounds; D013141:Spiro Compounds; C588178:negundoin A; D007455:Iodine