Crystal structure and absolute configuration of the hydrobromide salt of (-)-2-exo-aminonorbornane-2-carboxylic acid

Apgar, P. A.; Ludwig, Martha

doi:10.1021/ja00758a040

Cited by 18 publications

(12 citation statements)

References 1 publication

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“…Selected torsion angles are given in Table 2. The values of the bond lengths and angles are in agreement with literature data on the geometry of other norbomane amino acids (Apgar & Ludwig, 1972;Glass, Hojjatie, Sabahi, Steffen & Wilson, 1990).…”

Section: -Xsupporting

confidence: 89%

A Conformationally Restricted Aspartic Acid Analogue

Buñuel¹,

Cativiela²,

Dı́az-de-Villegas³

et al. 1996

Acta Crystallogr C

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Section: -Xsupporting

confidence: 89%

A Conformationally Restricted Aspartic Acid Analogue

Buñuel¹,

Cativiela²,

Dı́az-de-Villegas³

et al. 1996

Acta Crystallogr C

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“…The quantitative estimate we use is the sum of the squares of the distances between the atoms in their best fitting positions. Amongst known structures we find the most closely symmetric (Ed2 = 0.0079 A2) is the hydrobromide salt of (-)-2-exo-aminonorbornane-2-carboxylic acid, 14 (15), and the most distorted (Ed2 = 0.0703 A2) is 3-exo-(N-benzyl-N-methylaminomethy1)-2-endo-norbornanol, 15 (16). Altona and Sundaralingam (10) also give the latter as the most distorted norbornane nucleus in a known structure.…”

mentioning

confidence: 92%

Unusual Long-Range Spin–Spin Coupling in Norbornane-2,3-diones. Proton Magnetic Resonance Spectrum and X-Ray Structure Analysis of 6-endo-Bromo-1,5,5-trimethylnorbornane-2,3-dione

Hambly¹,

Leitch²,

Yates³

et al. 1973

Can. J. Chem.

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Several norbornane-2,3-diones show in their proton magnetic resonance spectra an unusual longrange spin-spin coupling, JJ,6, = 1.0-1.5 HZ. An X-ray structure analysis of 6-~trclo-bromo-1,5,5-trimethylnorbornane-2,3-dione shows that the norbornane framework deviates only slightly from mirror symmetry. This makes it unlikely that the ~~n u s u a l coupling in the norbornane-2,3-diones is due to distortion of the norbornane framework and lends credence to the view that it is due to substituent effects.Plusieurs norbornanedione-2.3 possedent dans leur spectre r.m.n. d u proton un couplage spin-spin A longue distance qui est ili~lsitc JJ+6, = 1.0-1.5 Hz. U n e analyse par rayons-)< de la structure de I'endobromo-6 trimcthyl-1,5,5 norbornanedione-2,3 niontre que le squelette d u norbornane devie tres peu de la synietrie par rapport a Lln niiroir. C e resultat implique qu'il est peu probable que lecouplage inusitisoit dil a i~n e distortion d u squelette ~L I norbornanc et amene a croire qu'il est dfi a des effets d e substituants.[Traduit p a r le journal]Can. J . Chern., 51,4076 (1973) Three types of long-range proton couplings (,J) have been generally recognized in the p.ni.r. spectra of norbornane derivatives (I), ciz. J,, (1.0-1.6 Hz), J,,,, (1.0-1.8 Hz), and J, , , , (1.7-4 Hz) (I). Each of these is associated with an approximately planar W geometry of the two protons and a three carbon atom chain (2) (2). Theoretical arguments have been advanced to account for the occurrence of significant longrange proton coupling in systems with this geometry (1). Although long-range coupling has been observed in four-bond systems involving three sp3 carbon atoms with other geometries, the coupling constants are usually appreciably smaller (< 0.5 Hz) ( I , 3, 4). ' It is therefore of considerable interest that Gagnaire and Rassat and their co-workers (5, 6) have observed a fourth type of significant long- 'We follow Sternhell (4) in arbitrarily attaching significance to coupling constants > 1 Hz because of our prime concern with the application of spin-spin coupling to structural problems. range coupling (J,,,) in the case of the two norbornane-2,3-diones 3

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“…The formation of the lactam (11) was surprising as the intermediate amino-nitrile (10, amino group exo) was expected based on the Strecker reaction of 2-norbornanone which yields the norbornane amino acid where the amino group is exo (confirmed by single crystal X-ray analysis). [15] Clearly, formation of (11) (ester group of amino-nitrile) and 1700 cm -1 (free acid carbonyl), [17] but no vibrations at 1640 cm -1 as would be expected for the lactam (11). [17] This suggests that lactam formation occurs during the nitrile hydrolysis step.…”

Section: Resultsmentioning

confidence: 99%

Some Stereochemical Aspects of the Strecker Synthesis and the Bucherer - Bergs Reaction

Wermuth¹,

Jenkins²,

Bott³

et al. 2004

Aust. J. Chem.

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Both the Strecker and Bucherer–Bergs reactions convert the norbornane keto ester methyl bicyclo[2.2.1]hept-6-one-2-endo-carboxylate into the lactam 6-endo-aminobicyclo[2.2.1]heptane-2-endo-carboxylic acid-γ-lactam-6-exo-carboxylic acid. This lactam is unusually stable and cannot be hydrolyzed to the corresponding amino acid. The stereochemistry in the Strecker reaction, in which the amino group is endo, is contrary to that expected from literature precedent. The stereochemistry in the Bucherer–Bergs reaction, in which the amino group is also endo, has been confirmed by X-ray crystallographic analysis of the intermediate spirohydantoin (±)-bicyclo[2.2.1]heptane-2-endo-carboxylic acid-6-spiro-5′-hydantoin.

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Crystal structure and absolute configuration of the hydrobromide salt of (-)-2-exo-aminonorbornane-2-carboxylic acid

Cited by 18 publications

References 1 publication

A Conformationally Restricted Aspartic Acid Analogue

A Conformationally Restricted Aspartic Acid Analogue

Unusual Long-Range Spin–Spin Coupling in Norbornane-2,3-diones. Proton Magnetic Resonance Spectrum and X-Ray Structure Analysis of 6-endo-Bromo-1,5,5-trimethylnorbornane-2,3-dione

Some Stereochemical Aspects of the Strecker Synthesis and the Bucherer - Bergs Reaction

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