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Volumn , Issue 6, 2007, Pages 989-991

A practical approach to stereochemically defined tetrahydrofurans from [5+2] oxidopyrylium-alkene cycloadducts

Author keywords

Beckmann fission; Cleavage; Cycloaddition; Oxidopyrylium; Stereoselectivity

Indexed keywords

3 OXIDOPYRYLIUM BETAINE; ALKENE DERIVATIVE; BETAINE; TETRAHYDROFURAN DERIVATIVE; UNCLASSIFIED DRUG;

EID: 34247167568     PISSN: 09365214     EISSN: None     Source Type: Journal    
DOI: 10.1055/s-2007-973866     Document Type: Article
Times cited : (8)

References (43)
  • 4
    • 0000012312 scopus 로고
    • Academic Press: Florida, Chap. 6
    • (d) Bartlett, P. A. Asymmetric Synthesis, Vol. III; Academic Press: Florida, 1984, Chap. 6, 411.
    • (1984) Asymmetric Synthesis , vol.3 , pp. 411
    • Bartlett, P.A.1
  • 8
    • 0000964586 scopus 로고    scopus 로고
    • For representative recent examples of tetrahydrofuran syntheses, see: a, Bird, C. W, Ed, Pergamon Press: Oxford
    • For representative recent examples of tetrahydrofuran syntheses, see: (a) Friedrichsen, W. In Comprehensive Heterocyclic Chemistry II, Vol. 2; Bird, C. W., Ed.; Pergamon Press: Oxford, 1996, 351.
    • (1996) Comprehensive Heterocyclic Chemistry II , vol.2 , pp. 351
    • Friedrichsen, W.1
  • 15
    • 0003905731 scopus 로고
    • Morrison, J. D, Ed, Academic Press: New York
    • (b) Paquette, L. A. Asymmetric Synthesis; Morrison, J. D., Ed.; Academic Press: New York, 1984.
    • (1984) Asymmetric Synthesis
    • Paquette, L.A.1
  • 37
    • 34247169772 scopus 로고    scopus 로고
    • General procedure for the reduction of cycloadduct 5: To cycloadduct 5 (1 mmol) dissolved in MeOH (12 mL) was added NiCl 2·6H2O (5 mmol) followed by distilled H 2O (2 mL, NaBH4 (2 mmol) was then added and the reaction mixture was stirred vigorously at r.t, The progress of the reaction was monitored by TLC using PE-EtOAc (9:1) and showed the complete disappearance of starting material after 15 min. The reaction was quenched with MeOH (10 mL) and the reaction mixture was filtered through a pad of celite and washed with MeOH. H2O (50 mL) was added to the combined filtrate, which was extracted with CH2Cl2 (3 x 15 mL, The combined CH 2Cl2 extract was dried over anhyd MgSO4, decanted through a cotton pad and concentrated in vacuo. The product was purified by column chromatography using silica gel (60-120 mesh) and PE-EtOAc as eluent
    • 4, decanted through a cotton pad and concentrated in vacuo. The product was purified by column chromatography using silica gel (60-120 mesh) and PE-EtOAc as eluent.
  • 38
    • 34247111098 scopus 로고    scopus 로고
    • 4, decanted through a cotton pad and concentrated in vacuo. The product was purified by column chromatography using silica gel (60-120 mesh) and PE-EtOAc (9:1) as eluent.
    • 4, decanted through a cotton pad and concentrated in vacuo. The product was purified by column chromatography using silica gel (60-120 mesh) and PE-EtOAc (9:1) as eluent.
  • 39
    • 34247138594 scopus 로고    scopus 로고
    • Typical procedure: A slight excess of SOCl2 (1 g, 8.4 mmol) in anhyd CCl4 (15 mL) at 0°C was added over a few minutes to a solution of oxime 6 (R, OEt, 1.5 g, 8 mmol) in CCl4, also at 0°C. Immediately after the addition, vigorous evolution of H 2 took place, the mixture was allowed to stir for another 10 min and then MeOH (10 mL) was added and the resulting solution was stirred for another 30 min. The solution was quenched with NaHCO3 and extracted using CH2Cl2 (2 x 30 mL, Evaporation of the solvent in vacuo and column chromatography of the residue on silica gel (EtOAc-PE, 1:9) gave tetrahydrofuran 7 (R, OEt) as a pale yellow oil (1.7 g, 90, IR: 2922, 2243, 1107, 1045 cm-1; 1H NMR (500 MHz, CDCl3, δ, 5.02 (dd, J, 1.5, 3.3 Hz, 1 H, 4.10 (m, 1 H, 4.06 (m, 1 H) 3.55 (m, 1 H, 3.34 (s, 3 H, 3.33 (m, 1 H, 2.60-2.50 m, 2 H, 2.1
    • 3Na: 222.1106; found: 222.1105.
  • 40
    • 33846003822 scopus 로고    scopus 로고
    • and references cited therein
    • (a) Ishiwata, A.; Akao, H.; Ito, Y. Org. Lett. 2006, 5525; and references cited therein,
    • (2006) Org. Lett , pp. 5525
    • Ishiwata, A.1    Akao, H.2    Ito, Y.3


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.