title: A torquoselective 6π electrocyclization approach to reserpine alkaloids.
abstract: A highly torquoselective thermal triene 6π electrocyclization controls the relative stereochemistry between the C3 and C18 stereocenters of the dodecahydroindolo[2,3-a]benzo[g]quinolizine skeleton of reserpine-type alkaloids. Employing a tandem cross-coupling/electrocyclization protocol allowed us to form the requisite triene and ensure its subsequent cyclization. A novel low-temperature dibromoketene acetal Claisen rearrangement established the requisite exocyclic dienylbromide precursor for the palladium-catalyzed cross-coupling reaction.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, 607 Charles E. Young Drive East, Los Angeles, California 90095-1569, USA.
authors.forename: Gregg A
authors.initials: GA
authors.lastname: Barcan
authors.forename: Ashay
authors.initials: A
authors.lastname: Patel
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
authors.forename: Ohyun
authors.initials: O
authors.lastname: Kwon
mesh_terms: D000080:Acetals / Q000737:chemistry; D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D015394:Molecular Structure; D010165:Palladium; D012110:Reserpine / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D000080:Acetals; D000470:Alkaloids; D010165:Palladium; D012110:Reserpine