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231223s2008 xx |||||o 00| ||eng c |
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|a 10.1002/mrc.2268
|2 doi
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|a pubmed24n0601.xml
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|a (DE-627)NLM180337513
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|a (NLM)18566984
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|a DE-627
|b ger
|c DE-627
|e rakwb
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|a eng
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| 100 |
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|a Pérez, Carlos
|e verfasserin
|4 aut
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|a On the unusual 2J(C2-H(f)) coupling dependence on syn/anti CHO conformation in 5-X-furan-2-carboxaldehydes
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|c 2008
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|a Text
|b txt
|2 rdacontent
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|a ƒaComputermedien
|b c
|2 rdamedia
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|a ƒa Online-Ressource
|b cr
|2 rdacarrier
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|a Date Completed 30.10.2008
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|a Date Revised 11.08.2008
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|a published: Print
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|a Citation Status MEDLINE
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|a 2008 John Wiley & Sons, Ltd.
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|a A remarkable difference for (2)J(C(2)-H(f)) coupling constant in syn and anti conformers of 5-X-furan-2-carboxaldehydes (X = CH(3), Ph, NO(2), Br) and a rationalization of this difference are reported. On the basis of the current knowledge of the Fermi-contact term transmission, a rather unusual dual-coupling pathway in the syn conformer is presented. The additional coupling pathway resembles somewhat that of the J(H-H) in homoallylic couplings, which are transmitted by hyperconjugative interactions involving the pi(C=C) electronic system. The homoallylic coupling pathway can be labeled as sigma*(C-H) <-- pi(C=C) --> sigma*(C-H). In the present case, this additional coupling pathway, using an analogous notation, can be labeled as sigma*(C(2)-C(C)) <-- LP(1)(O(1))...LP(2)(O(C)) --> sigma*(C(C)-H(f)) (sigma*(C(2)-C(C))) where O(1) and O(C) stand for the ring and carbonyl O atoms, respectively. This additional coupling pathway is not activated in the anti conformers since both oxygen lone pairs do not overlap
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|a Journal Article
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|a Research Support, Non-U.S. Gov't
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|a Aldehydes
|2 NLM
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|a Furans
|2 NLM
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| 700 |
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|a Suardíaz, Reynier
|e verfasserin
|4 aut
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|a Ortiz, Pedro J
|e verfasserin
|4 aut
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|a Crespo-Otero, Rachel
|e verfasserin
|4 aut
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|a Bonetto, Gloria M
|e verfasserin
|4 aut
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|a Gavín, José A
|e verfasserin
|4 aut
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| 700 |
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|a García de la Vega, José M
|e verfasserin
|4 aut
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| 700 |
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|a San Fabián, Jesús
|e verfasserin
|4 aut
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| 700 |
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|a Contreras, Rubén H
|e verfasserin
|4 aut
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| 773 |
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|i Enthalten in
|t Magnetic resonance in chemistry : MRC
|d 1985
|g 46(2008), 9 vom: 30. Sept., Seite 846-50
|w (DE-627)NLM098179667
|x 1097-458X
|7 nnns
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| 773 |
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|g volume:46
|g year:2008
|g number:9
|g day:30
|g month:09
|g pages:846-50
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|u http://dx.doi.org/10.1002/mrc.2268
|3 Volltext
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|d 46
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|h 846-50
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