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Volumn 48, Issue 12, 2007, Pages 2117-2122

Ranking the effect of [1A(ax), 1B(eq)] versus [1A(eq), 1B(ax)] cyclohexane ring substitution on the 1H chemical shifts of γ-methylene cyclohexane ring protons using 2,2-disubstituted adamantanes as models

Author keywords

2,2 Disubstituted adamantanes; 1H NMR chemical shifts; Axial cyclohexane conformer; Chemical shift difference

Indexed keywords

ADAMANTANE DERIVATIVE; CARBENE; CYCLOHEXANE DERIVATIVE;

EID: 33847027694     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2007.01.121     Document Type: Article
Times cited : (9)

References (39)
  • 6
    • 33847800907 scopus 로고
    • The shift occurring on the resonances of a carbon (upfield) and the attached protons (downfield) when a substituent is placed with a γ-gauche arrangement; after the original interpretation, which emphasized the steric interactions between hydrogen atoms and the C(γ) carbon atom (
    • The shift occurring on the resonances of a carbon (upfield) and the attached protons (downfield) when a substituent is placed with a γ-gauche arrangement; after the original interpretation, which emphasized the steric interactions between hydrogen atoms and the C(γ) carbon atom (. Eliel E.L., Bailey W.F., Kopp L.D., Willer R.L., Grant D.M., Bertrand R., Christensen K.H., Walling D.K., Duch M.W., Wenkert E., Schell F.M., and Cochran D.W. J. Am. Chem. Soc. 97 (1975) 322
    • (1975) J. Am. Chem. Soc. , vol.97 , pp. 322
    • Eliel, E.L.1    Bailey, W.F.2    Kopp, L.D.3    Willer, R.L.4    Grant, D.M.5    Bertrand, R.6    Christensen, K.H.7    Walling, D.K.8    Duch, M.W.9    Wenkert, E.10    Schell, F.M.11    Cochran, D.W.12
  • 8
    • 0001496662 scopus 로고
    • ), the stereoelectronic origin of this effect still remains unknown ( )
    • ), the stereoelectronic origin of this effect still remains unknown (. Barfield M. J. Am. Chem. Soc. 117 (1995) 2862 )
    • (1995) J. Am. Chem. Soc. , vol.117 , pp. 2862
    • Barfield, M.1
  • 22
    • 33847042471 scopus 로고    scopus 로고
    • 3 solution of amine 5 (50 mg) with TFA (two drops) inside the NMR tube and the mixture was left to equilibrate for several weeks before recording the NMR spectra; compounds 7 and 8 were prepared according to Ref. 11a.
  • 23
    • 10144256510 scopus 로고    scopus 로고
    • Between the numerous synthesized aminoadamantane derivatives, 2-alkyl-2-adamantanamines (e.g., compounds 2-5, 7, 8) were the most potent in vitro. For some representative examples see:
    • Between the numerous synthesized aminoadamantane derivatives, 2-alkyl-2-adamantanamines (e.g., compounds 2-5, 7, 8) were the most potent in vitro. For some representative examples see:. Kolocouris N., Kolocouris A., Foscolos G.B., Fytas G., Neyts J., Padalko E., Balzarini J., Snoeck R., Andrei G., and De Clercq E. J. Med. Chem. 39 (1996) 3307
    • (1996) J. Med. Chem. , vol.39 , pp. 3307
    • Kolocouris, N.1    Kolocouris, A.2    Foscolos, G.B.3    Fytas, G.4    Neyts, J.5    Padalko, E.6    Balzarini, J.7    Snoeck, R.8    Andrei, G.9    De Clercq, E.10
  • 27
    • 33847031519 scopus 로고    scopus 로고
    • Kolocouris, A.; Broadhurst, R. W.; Zikos, C. Bioorg. Med. Chem. Lett., submitted for publication.
  • 28
    • 0001024746 scopus 로고
    • 13C spectra of some 2,2-disubstituted adamantanes have been analyzed (
    • 13C spectra of some 2,2-disubstituted adamantanes have been analyzed (. Krishnamurthy V., Iyer P.S., and Olah G.A. J. Org. Chem. 48 (1983) 3373
    • (1983) J. Org. Chem. , vol.48 , pp. 3373
    • Krishnamurthy, V.1    Iyer, P.S.2    Olah, G.A.3
  • 30
    • 33847026622 scopus 로고    scopus 로고
    • MM3 (J. Am. Chem. Soc. 1993, 115, 11918) and MMFF94 (J. Comp. Chem. 1996, 17, 587) force fields are implemented in pcmodel (version 9.0), Serena Software.
  • 31
    • 33847049212 scopus 로고    scopus 로고
    • 1H correlation experiments a relaxation delay of 2 s was used; 2D NOE phase sensitive experiments were run using a mixing time of 1.5 s.
  • 32
    • 85012366532 scopus 로고
    • The interaction of groups that are close in space normally results in shielding of the carbon and deshielding of the protons involved. A remarkable demonstration of a steric compression effect is the δ- or ε-effect on the proton chemical shifts in some tetracyclic norbornyl systems, where the repulsion between groups separated by four or five bonds is so severe that the compressed proton appears uncommonly downfield by 3.1-3.5 ppm, but also, the uncompressed proton moves compensatingly upfield by 0.8-0.9 ppm ( )
    • The interaction of groups that are close in space normally results in shielding of the carbon and deshielding of the protons involved. A remarkable demonstration of a steric compression effect is the δ- or ε-effect on the proton chemical shifts in some tetracyclic norbornyl systems, where the repulsion between groups separated by four or five bonds is so severe that the compressed proton appears uncommonly downfield by 3.1-3.5 ppm, but also, the uncompressed proton moves compensatingly upfield by 0.8-0.9 ppm (. Winstein S.P., Carter P., Anet F.A.L., and Bourn A.J.R. J. Am. Chem. Soc. 95 (1973) 8005 )
    • (1973) J. Am. Chem. Soc. , vol.95 , pp. 8005
    • Winstein, S.P.1    Carter, P.2    Anet, F.A.L.3    Bourn, A.J.R.4
  • 34
    • 33847034962 scopus 로고    scopus 로고
    • For example, the chemical shift difference within the 4′,9′-H methylene in the case of 2-adamantanol or 2-t-Bu-adamantane is only ∼0.10 ppm; in these cases axial -OH or -t-Bu groups adopt an equatorial position with respect to the 1′-2′-3′-4′-5′-9′ cyclohexane ring (see Scheme 1, A = H, B = OH or t-Bu).
  • 35
    • 0001689154 scopus 로고
    • Stereodynamics of Cyclohexane and Substituted Cyclohexanes. Substituent A Values
    • Juaristi E. (Ed), VCH, New York
    • Bushweller C.H. Stereodynamics of Cyclohexane and Substituted Cyclohexanes. Substituent A Values. In: Juaristi E. (Ed). Conformational Behaviour of Six-Membered Rings (1995), VCH, New York 25
    • (1995) Conformational Behaviour of Six-Membered Rings , pp. 25
    • Bushweller, C.H.1
  • 37
    • 4744352080 scopus 로고    scopus 로고
    • 1H NMR spectra of compounds 1-19 was striking; this high spectrum resolution is important for the liquid-state NMR measurements focusing on how suitable reporter adamantane derivatives contact with the transmembrane portion of the influenza A M2 protein receptor embedded in lipid bilayers (see, for example, Ref. 12a and also: )
    • 1H NMR spectra of compounds 1-19 was striking; this high spectrum resolution is important for the liquid-state NMR measurements focusing on how suitable reporter adamantane derivatives contact with the transmembrane portion of the influenza A M2 protein receptor embedded in lipid bilayers (see, for example, Ref. 12a and also:. Wang J., Schnell J.R., and Chou J.J. Biochem. Biophys. Res. Commun. 324 (2004) 212 )
    • (2004) Biochem. Biophys. Res. Commun. , vol.324 , pp. 212
    • Wang, J.1    Schnell, J.R.2    Chou, J.J.3


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.