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Volumn , Issue 9, 1996, Pages 1425-1436

Polar and steric substituent effects in 5-exo-trig cyclizations of 1-aryl-4-penten-1-oxyl radicals

Author keywords

Alkoxyl radicals; Competition kinetics; Pyridinethiones; Tetrahydrofuran

Indexed keywords


EID: 3042622902     PISSN: 09473440     EISSN: None     Source Type: Journal    
DOI: 10.1002/jlac.199619960914     Document Type: Article
Times cited : (29)

References (34)
  • 19
    • 33749280160 scopus 로고    scopus 로고
    • The tetrahydrofurans 8 posses pleasant and the tetrahydropyrans 9 intense odors
    • The tetrahydrofurans 8 posses pleasant and the tetrahydropyrans 9 intense odors.
  • 20
    • 33749305116 scopus 로고    scopus 로고
    • note
    • It was assumed that the reactive hydrogen donor delivered its hydrogen with equivalent rate constant to all intermediate carbon radicals. Therefore, the analyzed product ratios should immediately reflect the stereo- and the regioselectivities of the alkoxyl radicals 2 in ring closure reactions.
  • 22
    • 85085781197 scopus 로고    scopus 로고
    • note
    • 3SnH is optimal for the synthesis of cyclic ethers 8 and 9. A decrease of the tin hydride concentration below 0.07 M give rise to detectable amounts (GC) of 1-aryl-4-penten-1-one.
  • 23
    • 33749290024 scopus 로고    scopus 로고
    • note
    • 3SnH] - 0.02 (R2 = 0.999).
  • 24
    • 33749270976 scopus 로고    scopus 로고
    • note
    • 1]methyl-5-(2-methyl-phenyl)tetrahydrofuran in 91% yield. According to NMR experiments no detectable amounts of hydrogen were incorporated from competitive hydrogen donors such as the α-hydrogen atoms of the reaction product making the tin deuteride and presumably the tin hydride in the reactions studied in tis work the only significant source of reactive hydrogen atoms.
  • 25
    • 85085782185 scopus 로고    scopus 로고
    • note
    • [1]. The 5-exo reactions are independent of the geometry of the substituents at the double bond and therefore similar cis-trans ratios of methyltetrahydrofurfurylmethyl radicals were obtained regardless whether the (E)- or the (Z)-alkenoxyl radical was used for ring closure.
  • 29
    • 0000938257 scopus 로고
    • 3SnH in great detail, but could not detect p-(4-pentenyloxy)anisol or p-(cyclopentyloxy)-anisol (GC) which would have been expected products from the proposed isomerization.
    • (1995) J. Phys. Chem. , vol.99 , pp. 3527-3531
    • Banks, J.T.1    Scaiano, J.C.2
  • 30
    • 0842341771 scopus 로고
    • [18]. - The calculations were performed by the AM1 method (M. J. S. Dewar, E. G. Zoebisch, E. F. Healy, J. J. P. Stewart, J. Am. Chem. Soc. 1985, 107, 3902-3909) which is implemented in the HpyerChem® software package. The geometries were optimized by using the UHF approximation and the Fletcher-Reeves algorithm.
    • (1985) J. Am. Chem. Soc. , vol.107 , pp. 3902-3909
    • Dewar, M.J.S.1    Zoebisch, E.G.2    Healy, E.F.3    Stewart, J.J.P.4
  • 31
    • 0006154340 scopus 로고
    • [17] (R. E. Elliot, W. G. Richards, J. Chem. Soc., Perkin Trans. 2, 1982, 943-945, and references cited therein). Thus, the interaction between the SOMO and the HOMO of olefins in intermolecular reactions will be more pronounced than the stabilization of the reactants by SOMO-LUMO intactions.
    • (1982) J. Chem. Soc., Perkin Trans. 2 , pp. 943-945
    • Elliot, R.E.1    Richards, W.G.2


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.