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Volumn 4, Issue 10, 2002, Pages 1787-1790

Synthesis of the C(1)-C(18) segment of lophotoxin and pukalide. Control of 2-alkenylfuran (E/Z)-configuration

Author keywords

[No Author keywords available]

Indexed keywords

COELENTERATE VENOM; EPOXIDE; FURAN DERIVATIVE; LOPHOTOXIN; NICOTINIC RECEPTOR; NICOTINIC RECEPTOR BLOCKING AGENT; PUKALIDE; TERPENE;

EID: 0037118343     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol025861m     Document Type: Article
Times cited : (52)

References (57)
  • 20
    • 33845551109 scopus 로고
    • For reviews on allenes, see: (h) Smadja, W. Chem. Rev. 1983, 83, 263.
    • (1983) Chem. Rev. , vol.83 , pp. 263
    • Smadja, W.1
  • 24
    • 0041496489 scopus 로고    scopus 로고
    • note
    • 10 but the details on its preparation are lacking. Reference 10b reports in a footnote that 2 can be prepared by reaction of the dianion of methyl acetoacetate with [(p-methoxybenzyl)-oxy]methyl chloride.
  • 27
    • 0030029851 scopus 로고    scopus 로고
    • We did not encounter significant problems with rearrangements in our preparation of 3. However, both a Brook rearrangement and a [1,2] TMS group shift have been reported for this same coupling under different conditions. See: (a) Cunico, R. F.; Nair, S. K. Synth. Commun. 1996, 26, 803.
    • (1996) Synth. Commun. , vol.26 , pp. 803
    • Cunico, R.F.1    Nair, S.K.2
  • 32
    • 0041997444 scopus 로고    scopus 로고
    • note
    • These conditions were first developed with ethyl acetoacetate as the β-keto ester component. The corresponding 2-alkenylfuran product was difficult to purify, however. Importantly, our originally reported conditions employing THF as a solvent were completely unsuccessful, resulting in no reaction. Use of ethanol at reflux led to product, but in low yields; reaction in dimethylformamide (starting at room temperature and warming to ca. 85 °C) was successful (55%) but not always reproducible. Reaction in acetonitrile at reflux was slow; but use of a hot 10:1 acetonitrile/water mixture resulted in reproducible yields of ca. 55%.
  • 47
    • 0041496488 scopus 로고    scopus 로고
    • note
    • (Z)-14 can be isomerized to the corresponding (E)-isomer, but this process is much slower than the isomerization of (Z)-6. Treatment of (Z)-14 with 10 equiv of diphenyl diselenide in tetrahydrofuran at reflux affords, after 8 d, a 4.4:1 (E):(Z) ratio of alkenes.
  • 53
    • 0041997442 scopus 로고    scopus 로고
    • note
    • 1H NMR NOE spectroscopic studies on the vinyl iodide products. In the case of (Z)-6, a significant amount of alkene isomerization was noted, and the vinyl iodide product was isolated as a ca. 1:6 (E):(Z) mixture. In the case of (E)-7, little to no isomerization occurred.
  • 55
    • 0000217402 scopus 로고
    • Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon: Oxford
    • Wipf, P. In Comprehensive Organic Synthesis; Trost, B. M., Fleming, I., Paquette, L. A., Eds.; Pergamon: Oxford, 1991; Vol. 5; pp 827-874.
    • (1991) Comprehensive Organic Synthesis , vol.5 , pp. 827-874
    • Wipf, P.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.