Preparation of Single-Enantiomer Biofunctional Molecules with (<i>S</i>)-2-Methoxy-2-(1-naphthyl)propanoic Acid

Ichikawa, Akio; Ono, Hiroshi

doi:10.1271/bbb.80100

Cited by 8 publications

(3 citation statements)

References 12 publications

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“…The reaction time was 18 h. The crude product was purified by HPLC on a pre-packed Si-5 column (n-hexane/EtOAc). For details, see references [6,8].…”

Section: Preparation Of Ester 14mentioning

confidence: 99%

“…[1,2] Therefore, these acids are attractive for the development of new methods for the preparation and structural elucidation of single-enantiomers. [1][2][3][4][5][6][7][8][9][10][11][12][13] We have previously reported the synthesis of acids 1-3 [10,12,13] and applied them as agents for the enantioresolution of biofunctional molecules. [6][7][8] Acids 1-3 exhibited powerful chiral-resolving ability in the HPLC separation of their diastereomeric esters and amides.…”

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confidence: 99%

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Naphthyl Groups in Chiral Recognition: Structures of Salts and Esters of 2‐Methoxy‐2‐naphthylpropanoic Acids

Ichikawa

Ono

Mikata

2012

Chemistry An Asian Journal

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The crystal structures of salt 8, which was prepared from (R)-2-methoxy-2-(2-naphthyl)propanoic acid ((R)-MβNP acid, (R)-2) and (R)-1-phenylethylamine ((R)-PEA, (R)-6), and salt 9, which was prepared from (R)-2-methoxy-2-(1-naphthyl)propanoic acid ((R)-MαNP acid, (R)-1) and (R)-1-(p-tolyl)ethylamine ((R)-TEA, (R)-7), were determined by X-ray crystallography. The MβNP and MαNP anions formed ion-pairs with the PEA and TEA cations, respectively, through a methoxy-group-assisted salt bridge and aromatic CH⋅⋅⋅π interactions. The networks of salt bridges formed 2(1) columns in both salts. Finally, (S)-(2E,6E)-(1-(2) H(1) )farnesol ((S)-13) was prepared from the reaction of (2E,6E)-farnesal (11) with deuterated (R)-BINAL-H (i.e., (R)-BINAL-D). The enantiomeric excess of compound (S)-13 was determined by NMR analysis of (S)-MαNP ester 14. The solution-state structures of MαNP esters that were prepared from primary alcohols were also elucidated.

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“…The reaction time was 18 h. The crude product was purified by HPLC on a pre-packed Si-5 column (n-hexane/EtOAc). For details, see references [6,8].…”

Section: Preparation Of Ester 14mentioning

confidence: 99%

mentioning

confidence: 99%

Naphthyl Groups in Chiral Recognition: Structures of Salts and Esters of 2‐Methoxy‐2‐naphthylpropanoic Acids

Ichikawa

Ono

Mikata

2012

Chemistry An Asian Journal

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“…We studied on three chiral resolving agents [i.e., MαNP acid (2), MβNP acid (3), and M9PP acid (4)] based on their enantioresolution of chiral alcohols and elucidation of absolute configurations [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The resolving ability of 2 is superior to that of 1 in normal phase HPLC.…”

Section: Introductionmentioning

confidence: 99%

Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database

2015

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Abstract:Conformations of the crystalline 3,3,3-trifluoro-2-methoxy-2-phenylpropanamide derivatives (MTPA amides) deposited in the Cambridge Structural Database (CSD) were examined statistically as Racid-enantiomers. The majority of dihedral angles (48/58, ca. 83%) of the amide carbonyl groups and the trifluoromethyl groups ranged from -30° to 0° with an average angle θ 1 of −13°. The other conformational properties were also clarified: (1) one of the fluorine atoms was antiperiplanar (ap) to the amide carbonyl group, forming a staggered conformation; (2) the MTPA amides prepared from primary amines showed a Z form in amide moieties; (3) in the case of the MTPA amide prepared from a primary amine possessing secondary alkyl groups (i.e., Mosher-type MTPA amide), the dihedral angles between the methine groups and the carbonyl groups were syn and indicative of a moderate conformational flexibility; (4) the phenyl plane was inclined from the O-Cchiral bond of the methoxy moiety with an average dihedral angle θ 2 of +21°; (5) the methyl group of the methoxy moiety was ap to the ipso-carbon atom of the phenyl group.

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X ‐ray Crystallography and ¹ H NMR Anisotropy Methods for Determination of Absolute Configurations

Harada

2013

Stereoselective Synthesis of Drugs and Natural Products

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In the stereoselective synthesis of drugs and natural products, it is critical to determine the absolute configurations (ACs) of reaction products. To determine the ACs of chiral compounds, many spectroscopic and diffraction methods have been developed. Among them, X‐ray crystallographic Bijvoet and circular dichroism (CD) exciton chirality methods enable one to determine ACs in a nonempirical manner. On the other hand, X‐ray crystallography using a chiral internal reference and 1 H nuclear magnetic resonance (NMR) spectroscopy using a chiral anisotropy reagent are relative and/or empirical methods, but they are more practical for organic synthetic studies because the methods have the advantage of preparing enantiopure compounds by high‐performance liquid chromatography (HPLC) separation and of establishing unambiguously the ACs. As chiral reagents useful for both the preparation of enantiopure compounds by HPLC separation and the simultaneous determination of their ACs, we have developed camphorsultam‐dichlorophthalic acid (CSDP acid) for X‐ray crystallography and 2‐methoxy‐2‐(1‐naphthyl)propionic acid (MαNP acid) for 1 H NMR spectroscopy and X‐ray crystallography. In this chapter, the outline and applications of these X‐ray and NMR methods are explained using various interesting data.

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Preparation of Single-Enantiomer Biofunctional Molecules with (S)-2-Methoxy-2-(1-naphthyl)propanoic Acid

Cited by 8 publications

References 12 publications

Naphthyl Groups in Chiral Recognition: Structures of Salts and Esters of 2‐Methoxy‐2‐naphthylpropanoic Acids

Naphthyl Groups in Chiral Recognition: Structures of Salts and Esters of 2‐Methoxy‐2‐naphthylpropanoic Acids

Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database

X ‐ray Crystallography and ¹ H NMR Anisotropy Methods for Determination of Absolute Configurations

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Preparation of Single-Enantiomer Biofunctional Molecules with (S)-2-Methoxy-2-(1-naphthyl)propanoic Acid

Cited by 8 publications

References 12 publications

Naphthyl Groups in Chiral Recognition: Structures of Salts and Esters of 2‐Methoxy‐2‐naphthylpropanoic Acids

Naphthyl Groups in Chiral Recognition: Structures of Salts and Esters of 2‐Methoxy‐2‐naphthylpropanoic Acids

Characteristic Conformation of Mosher’s Amide Elucidated Using the Cambridge Structural Database

X ‐ray Crystallography and 1 H NMR Anisotropy Methods for Determination of Absolute Configurations

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X ‐ray Crystallography and ¹ H NMR Anisotropy Methods for Determination of Absolute Configurations