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Volumn , Issue 5, 2005, Pages 789-792

Enantioselective annulation using Nazarov reagent: Synthesis of (+)-preoleanatetraene

Author keywords

Annulation; Asymmetric synthesis; Natural products; Preoleanatetraene; Terpenoids; Total synthesis

Indexed keywords

BICYCLO COMPOUND; ENAMINE; NATURAL PRODUCT; NAZAROV REAGENT; PREOLEANATETRAENE; REAGENT; TERPENOID; TRITERPENE; UNCLASSIFIED DRUG;

EID: 15944381259     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-2005-864798     Document Type: Article
Times cited : (11)

References (25)
  • 7
    • 0037560988 scopus 로고    scopus 로고
    • Although the biosynthesis of β-amyrin is known to proceed via 2,3-oxidosqualene, the fact that β-amyrin has been obtained after enzymatic cyclization of the 2,3-epoxide of racemic 1 should be also taken into account. Furthermore, oxidosqualene cyclase mutagenesis experiments, included those in which achilleol A and camelliol C are biosynthesized by mutant OSC, suggested that relatively few changes in the enzyme are needed to alter product specificity. These findings ultimately supported the existence of alternative pathways in the biosynthesis of terpenoids. For OCS mutagenesis experiments, see: (a) Segura, M. J. R.; Jackson, B. E.; Matsuda, S. P. T. Nat Prod. Rep. 2003, 20, 304.
    • (2003) Nat Prod. Rep. , vol.20 , pp. 304
    • Segura, M.J.R.1    Jackson, B.E.2    Matsuda, S.P.T.3
  • 11
    • 0035966238 scopus 로고    scopus 로고
    • To our knowledge, only Theodorakis et al. have assayed the enantioselective variant of this reaction in their synthesis of (-)-acanthoic acid. Although the condensation reaction was attempted in the presence of different optically active catalysts, the highest ee obtained were of 60%: Ling, T.; Chowdhury, C.; Kramer, B. A.; Vong, B. G.; Palladino, M. A.; Theodorakis, E. A. J. Org. Chem. 2001, 66, 8843.
    • (2001) J. Org. Chem. , vol.66 , pp. 8843
    • Ling, T.1    Chowdhury, C.2    Kramer, B.A.3    Vong, B.G.4    Palladino, M.A.5    Theodorakis, E.A.6
  • 14
    • 12044254693 scopus 로고
    • Reports by Barton and van Tamelen, showing that the use of different epimers in OSC-induced cyclizations, led to different results constituted an additional argument to pursue the enantioselective synthesis of these irregular triterpenes: Abe, I.; Rohmer, M.; Preswich, G. D. Chem. Rev. 1993, 93, 2189.
    • (1993) Chem. Rev. , vol.93 , pp. 2189
    • Abe, I.1    Rohmer, M.2    Preswich, G.D.3
  • 17
    • 33750286079 scopus 로고
    • (a) Nazarov, I. N.; Zavyalov, S. I. Zh. Obshch. Khim. 1953, 23, 1703; Chem. Abstr. 1954, 48, 13667h.
    • (1954) Chem. Abstr. , vol.48
  • 19
    • 15944404124 scopus 로고    scopus 로고
    • note
    • +: 273.1467; found: 273.1463.
  • 20
    • 15944401902 scopus 로고    scopus 로고
    • note
    • 1H NMR (800 MHz) spectroscopy, by integrating the AB quartets of the major and minor components.
  • 23
    • 0036637573 scopus 로고    scopus 로고
    • (b) Although recently both polypodatetraenes have been reported from (-)-albicanol and (-)-drimenol by Akita et al., the method used by these authors supposed an elongation of the carbon chain of the sesquiterpenic precursors, as a previous step to the key C-20+C-10 coupling process: Kirosita, M.; Ohtsuka, M.; Nakamura, O.; Akita, H. Chem. Pharm. Bull. 2002, 50, 930.
    • (2002) Chem. Pharm. Bull. , vol.50 , pp. 930
    • Kirosita, M.1    Ohtsuka, M.2    Nakamura, O.3    Akita, H.4


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.