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Tetrahedron Letters
Volumn 34, Issue 1, 1993, Pages 87-90
Metallic base-induced and Lewis acid-catalyzed nitrone cycloadditions to allyl alcohol dipolarophiles. Highly effective regio- and stereocontrol
Author keywords

Allyl alcohols; Allyl alkoxides; Dipolar cycloaddition; Lewis acid catalysis; Nitrone; Regiocontrol; Stereocontrol
Indexed keywords

ISOXAZOLIDINE DERIVATIVE;
EID: 0027398063     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(00)60064-3     Document Type: Article
Times cited : (68)
References (13)
  • 1
    • 84918745841 scopus 로고    scopus 로고
    • Kanemasa, S.; Uemura, T.; Wada, E. Tetrahedron Lett. in press.
  • 4
    • 84918717511 scopus 로고    scopus 로고
    • Kanemasa, S.; Nishiuchi, M. Submitted for publication.
  • 5
    • 0000024191 scopus 로고
    • 1.3-Dipolare Cycloadditionen, L. Charakterisierung ungesättigter Verbindungen als Acyl-nitron-Addukte
    • The same reaction was previously performed by Huisgen and coworkers, but stereochemistry of the products remains ambigous
    • (1969) Chemische Berichte , vol.102 , pp. 1117-1128
    • Huisgen1    Hauck2    Seidl3    Burger4
  • 6
    • 84918757245 scopus 로고    scopus 로고
    • All new compounds down in this report were characterized on the basis of analytical and spectral data.
  • 7
    • 84918716972 scopus 로고    scopus 로고
    • This reaction is so slow at room temperature to give a 73:27 mixture of exo-3b and endo-4 only in 33% yield after 6d.
  • 8
    • 84918735436 scopus 로고    scopus 로고
    • 2), 79.34 (C-5), 85.54 (C-3), 114.06, 122.04, 128.71, 129.17, 129.24, 133.60, 151.18 (each Ph), and 197.89 (PhCO); MS (rel intensity, %) m/z 298, M [[Truncated]]
  • 9
    • 84918744359 scopus 로고    scopus 로고
    • Hemiacetals 5a,b are always mixtures of diastereomers due to the mixed stereochemistry at 6-position. The same to their O-alkylated derivatives 6a,b.
  • 10
    • 84918744495 scopus 로고    scopus 로고
    • 1H NMR and NOE spectrum (Scheme 2).
  • 11
    • 84918722494 scopus 로고    scopus 로고
    • 2), 35:65 (THF), <1:99 (DMF).
  • 12
    • 84918735119 scopus 로고    scopus 로고
    • One equivalent of 2b was used therein. Formation of acetal exo-6b indicates that the rapid O-alkylation took place in the presence of a strong Lewis acid.
  • 13
    • 84918742816 scopus 로고    scopus 로고
    • The 1:1 catalyst/dipole complex B partly precipitates out of the dichloromethane solution (70%) due to poor solubility. Evaporation of the filtrate affords a further fraction (30%) of the same complex. The complex B reacted with free alcohol 2b to give exo-3b, while B catalyzed the reaction of 1 with 2b to give exo-5b, both as single isomers.

* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.