title: Construction of tricyclic enone, a common precursor for aphidicolane and stemodane B/C/D-ring system.
abstract: Synthesis of a tricyclic enone (B/C/D ring system), a common key precursor for the aphidicolane- and stemodane-type diterpene, is described. The key reaction for the construction of the quaternary carbon center is allylation of epoxide at the more substituted carbon with an organotitanium reagent. Asymmetric reduction with DIP-Cl followed by stereoselective cyclization of spirocyclic ketone and the functional group modification gave the desired tricyclic enone in good yield.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. t-tanaka@phs.osaka-u.ac.jp
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Tanaka
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Kei
authors.initials: K
authors.lastname: Hiramatsu
authors.forename: Kazuo
authors.initials: K
authors.lastname: Murakami
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yoshino
authors.forename: Debasis
authors.initials: D
authors.lastname: Patra
authors.forename: Chuzo
authors.initials: C
authors.lastname: Iwata
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Ohno
mesh_terms: D000080:Acetals / Q000737:chemistry*; D016590:Aphidicolin / Q000737:chemistry*; D004224:Diterpenes / Q000737:chemistry*; D015394:Molecular Structure; D011753:Pyrones / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry*
chemical_list: D000080:Acetals; D004224:Diterpenes; D011753:Pyrones; D014315:Triterpenes; C513991:tricyclo(6.3.1.0(1,6))dodec-5-ene-4,9-dione 9,9-ethylene acetal; D016590:Aphidicolin; C074341:stemodin; C450163:stemodinone