Conformation and crystal structures of 1-amino­cyclo­hexa­neacetic acid (β3,3Ac6c) in N-protected derivatives1

نویسندگان

  • Naiem Ahmad Wani
  • Vivek K. Gupta
  • Rajni Kant
  • Subrayashastry Aravinda
  • Rajkishor Rai
چکیده

N-Protected derivatives of 1-amino-cyclo-hexa-neacetic acid (β(3,3)-Ac6c), namely Valeroyl-β(3,3)-Ac6c-OH [2-(1-pentanamidocyclohexyl)acetic acid, C13H23NO3], (I), Fmoc-β(3,3)-Ac6c-OH [2-(1-{[(9H-fluoren-9-yloxy)carbonyl]amino}cyclohexyl)acetic acid, C23H25NO4], (II), and Pyr-β(3,3)-Ac6c-OH {2-[1-(pyrazine-2-amido)cyclohexyl]acetic acid, C13H17N3O3}, (III), were synthesized and their conformational properties were determined by X-ray diffraction analysis. The backbone torsion angles (ϕ, θ) for β(3,3)-Ac6c-OH are restricted to gauche conformations in all the derivatives, with a chair conformation of the cyclo-hexane ring. In the crystal structure of (I), the packing of mol-ecules shows both carb-oxy-lic acid R 2 (2)(8) O-H⋯O and centrosymmetric R (2) 2(14) N-H⋯O hydrogen-bonding inter-actions, giving rise to chains along the c-axis direction. In (II), centrosymmetric carb-oxy-lic acid R 2 (2)(8) O-H⋯O dimers are extended through N-H⋯O hydrogen bonds and together with inter-ring π-π inter-actions between Fmoc groups [ring centroid distance = 3.786 (2) Å], generate a layered structure lying parallel to (010). In the case of compound (III), carb-oxy-lic acid O-H⋯Npyrazine hydrogen bonds give rise to zigzag ribbon structures extending along the c-axis direction.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Conformational analysis of N- and C-terminally protected tripeptide model glycyl-isoleucine-glycyl: An ab initio and DFT study

An ab initio and density functional theory (DFT) study about conformational analysis of tripeptide model HCO−GLY−L−ILE−GLY−NH2 is presented. The tripeptide was scanned about initial, central, and final residues, separately while for every scanning procedure the two other residues had been kept in the β conformation and side chain (SC) dihedral angles were maintained on the gauche− (g‾) state (χ...

متن کامل

Effect of Alkyl Substituents on the Hydrogen Bonding and Molecular Structure of Benzophenylhydroxamic Acids Crystal structure of UO2 Complex of p-Isopropylbenzophenylhydroxamic Acid

The effect of alkyl substituents on the C-phenyl and/or the N-Phenyl ring of benzophenylhydroxamic acid on their molecular structure and hydrogen bonding has been investigated. The predominant configuration in CHCl3 is determined by steric and electronic effects. Substituents on the C-phenyl ring favor the cis configuration, while substituents in the N-phenyl ring favor a trans c...

متن کامل

Plumbum(II) and Zinc(II) Complexes with 5-Chlorosalicylic Acid: Structure and Propertie

Abstract: Two new transition metal complexes, containing the acidic ligand 5-chlorosalicylic acid (H2L5), and 1,10-phenanthroline(phen) and 1,3-Di(4-pyridyl)propane (bpp) as secondary ligands are reported. They are formulated as {[Pb(HL5)2(phen)(H2O)]·H2O}n(1), [Zn2(HL5)4(bpp)2]n(2). All the complexes are characterized by single-crystal X-ray diffractions. Compoud 1 crystallizes in the triclini...

متن کامل

Theoretical investigations on molecular structure, NBO, HOMO-LUMO and MEP analysis of two crystal structures of N-(2-benzoyl-phenyl) oxalyl: A DFT study

The N-(2-benzoyl-phenyl) oxalyl derivatives are important models for studying of three-centered intramolecular hydrogen bonding in organic molecules. The quantum theoretical calculations for two crystal structures of N-(2-benzoyl-phenyl) oxalyl (compounds I and II) were performed by Density Functional Theory (B3LYP method and 6-311+G* basis set). From the optimized structures, geometric paramet...

متن کامل

Microwave Assisted Selective Synthesis of four Chromanones Via Biscyclization Method in the Presence of Polyphosphoric Acid and Crystal Structure Determination of Their Dicarboxylic Acids

Microwave irradiation is used in the synthesis of four tricyclic chromanones 11-14. The chromanone 14 and 12 are selectively formed thermally and under microwave in the presence of polyphosphoric acid (PPA) from the same dicarboxylic acid 9, respectively. The crystal structures of the two diacids are also reported. The corresponding ortho and meta isomers of diacids crystallize in the space...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 70  شماره 

صفحات  -

تاریخ انتشار 2014