title: Studies on C20-diterpenoid alkaloids: synthesis of the hetidine framework and its application to the synthesis of dihydronavirine and the atisine skeleton.
abstract: The full details of a synthesis of the hetidine framework of the C20-diterpenoid alkaloids and its conversion to the atisine core structure are reported. The application of the hetidine framework to the synthesis of dihydronavirine, which is the formal reduction product of the natural product navirine, is also described. Key to the success of these studies is the use of a Ga(III)-catalyzed cycloisomerization reaction of alkynylindenes to prepare a [6-7-6] framework that was advanced to the hetidine skeleton. Furthermore, a Michael/aldol sequence was developed for the construction of the bicyclo[2.2.2] framework that is characteristic of the hetidines and atisines.
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Hamlin
authors.forename: David
authors.initials: D
authors.lastname: Lapointe
authors.forename: Kyle
authors.initials: K
authors.lastname: Owens
authors.forename: Richmond
authors.initials: R
authors.lastname: Sarpong
mesh_terms: D000470:Alkaloids / Q000138:chemical synthesis* / Q000737:chemistry; D000480:Alkynes / Q000737:chemistry*; D001688:Biological Products / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003500:Cyclization; D004224:Diterpenes / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D000470:Alkaloids; D000480:Alkynes; D001688:Biological Products; D004224:Diterpenes; C509541:atisinium chloride; C000595009:dihydronavirine