title: A divergent route to 9, 10-oxygenated tetrahydroprotoberberine and 8-oxoprotoberberine alkaloids: synthesis of (±)-isocorypalmine and oxypalmatine.
abstract: A new route which is germane to the synthesis of 9,10-oxygenated tetrahydroprotoberberines and 8-oxoprotoberberines is described. The route features the use of a diester (14) generated from reaction of dimethylmalonate with an aryl halide in the presence ofn-butyllithium. The amide17prepared in subsequent steps is a versatile precursor for the synthesis of tetrahydroprotoberberine and 8-oxoprotoberberine scaffolds using standard high-yielding reactions. In this manner, (±)-isocorypalmine and oxypalmatine have been synthesized in 23% and 22 % yields respectively.
authors.affiliation: Hunter College, City University of New York, 695 Park Avenue, NY 10065, USA ; The Graduate Center, City University of New York, 365 5th Avenue, NY 10016, USA.
authors.forename: Satish
authors.initials: S
authors.lastname: Gadhiya
authors.affiliation: Hunter College, City University of New York, 695 Park Avenue, NY 10065, USA.
authors.forename: Shashikanth
authors.initials: S
authors.lastname: Ponnala
authors.affiliation: Hunter College, City University of New York, 695 Park Avenue, NY 10065, USA ; The Graduate Center, City University of New York, 365 5th Avenue, NY 10016, USA.
authors.forename: Wayne W
authors.initials: WW
authors.lastname: Harding
keywords: 8-oxoprotoberberine; Isocorypalmine; Oxypalmatine; THPB; Tetrahydroprotoberberine