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Volumn 48, Issue 34, 2009, Pages 6296-6299

Nucleophilic opening of oxabicyclic ring systems

Author keywords

Asymmetric synthesis; Lewis acids; Perhydroindoles; Perhydroquinolines; Ring opening

Indexed keywords

ASYMMETRIC SYNTHESIS; LEWIS ACIDS; PERHYDROINDOLES; PERHYDROQUINOLINES; RING OPENING;

EID: 70349905136     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200902046     Document Type: Article
Times cited : (20)

References (35)
  • 6
    • 57349166544 scopus 로고    scopus 로고
    • for a recent review on the chemistry of the aeruginosins, see
    • c) for a recent review on the chemistry of the aeruginosins, see: K. Ersmark, J. R. Del Vaile, S. Hanessian, Angew. Chem. 2008, 120, 1220;
    • (2008) Angew. Chem , vol.120 , pp. 1220
    • Ersmark, K.1    Del Vaile, J.R.2    Hanessian, S.3
  • 20
    • 70349950416 scopus 로고    scopus 로고
    • The oxabicyclic substrates were prepared by an enantioselective Diels-Alder reaction of furan and bromoacrolein with the tryptophan-derived oxazaborolidine catalyst described by Corey and Loh see references [3] and [4, The L-tryptophan-derived catalyst was used for the reactions in entries 3 and 4 of Table 2 and entries 5 and 6 of Table 3; the D-tryptophan-derived catalyst was used for the reactions in entries 1 and 2 of Table 2 and entries 1-4 of Table 3
    • The oxabicyclic substrates were prepared by an enantioselective Diels-Alder reaction of furan and bromoacrolein with the tryptophan-derived oxazaborolidine catalyst described by Corey and Loh (see references [3] and [4]). The L-tryptophan-derived catalyst was used for the reactions in entries 3 and 4 of Table 2 and entries 5 and 6 of Table 3; the D-tryptophan-derived catalyst was used for the reactions in entries 1 and 2 of Table 2 and entries 1-4 of Table 3.
  • 21
    • 70349965917 scopus 로고    scopus 로고
    • To the best of our knowledge, there is only one example in the literature of the opening of an oxabicycloheptene by displacement of a bridging C - O bond, namely, the ring opening of 2-methylthio-7-oxabicyclo[2.2.1]heptene by silyl enol ethers in the presence of TBDMSOTf: I. Yamamoto, K. Narasaka, Chem. Lett. 1995, 1129. The ring opening proceeds by cleavage of the C - O bond, and net substitution occurs with retention of configuration. The stereochemical result underscores the fact that the reaction proceeds by heterolytic cleavage of the C - O bond to give a secondary carbocation, which is stabilized significantly by the vinyl sulfide.
    • To the best of our knowledge, there is only one example in the literature of the opening of an oxabicycloheptene by displacement of a bridging C - O bond, namely, the ring opening of 2-methylthio-7-oxabicyclo[2.2.1]heptene by silyl enol ethers in the presence of TBDMSOTf: I. Yamamoto, K. Narasaka, Chem. Lett. 1995, 1129. The ring opening proceeds by cleavage of the C - O bond, and net substitution occurs with retention of configuration. The stereochemical result underscores the fact that the reaction proceeds by heterolytic cleavage of the C - O bond to give a secondary carbocation, which is stabilized significantly by the vinyl sulfide.
  • 22
    • 70349964238 scopus 로고    scopus 로고
    • -3, T=223 K, reflections collected: 18793, independent reflections: 4693 (R(int) = 0.15), R(all) = 0.0678, wR(gt) = 0.1315. CCDC 721256 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data-request/cif.
    • -3, T=223 K, reflections collected: 18793, independent reflections: 4693 (R(int) = 0.15), R(all) = 0.0678, wR(gt) = 0.1315. CCDC 721256 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data-request/cif.
  • 23
    • 70349946927 scopus 로고    scopus 로고
    • ORTEP representation of the/-bromobenzoate ester of 20b (probability ellipsoids at 50%; Table 3, entry 5). Figure Presented.
    • ORTEP representation of the/"-bromobenzoate ester of 20b (probability ellipsoids at 50%; Table 3, entry 5). Figure Presented.
  • 24
    • 70349964260 scopus 로고    scopus 로고
    • We considered the mechanistic possibility of pinacol-type rearrangement sequences. However, the formation of the aminal product inevitably positions the tertiary hydroxy group at the other ring-fusion carbon atom. X-ray crystallographic analysis of the p-bromobenzoate ester of 20b proved critical in ruling out this option.
    • We considered the mechanistic possibility of pinacol-type rearrangement sequences. However, the formation of the aminal product inevitably positions the tertiary hydroxy group at the other ring-fusion carbon atom. X-ray crystallographic analysis of the p-bromobenzoate ester of 20b proved critical in ruling out this option.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.