title: An efficient total synthesis of ruprechstyril from Ruprechtia tangarana.
abstract: A short total synthesis of natural isocarbostyril ruprechstyril (3-n-pentyl-6-methoxy-8-hydroxy-1(2H)-isoquinolinone) isolated from Ruprechtia tangarana is reported. 6,8-Dimethoxy-3-pentylisocoumarin obtained by condensation of 3,5-dimethoxyhomophthalic anhydride with hexanoyl chloride was smoothly converted to O-methylruprechstyril by refluxing with methanamide. Regioselective demethylation of the latter using anhydrous aluminium chloride in dichloromethane furnished the ruprechstyril. Complete demethylation to give (6-desmethoxyruprechstyril) was achieved using same reagent in ethanethiol.
authors.affiliation: Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan. aamersaeed@yahoo.com
authors.forename: Aamer
authors.initials: A
authors.lastname: Saeed
mesh_terms: D006912:Hydroxyquinolines / Q000138:chemical synthesis*; D015394:Molecular Structure; D019664:Polygonaceae / Q000737:chemistry*
chemical_list: D006912:Hydroxyquinolines; C479808:ruprechstyril