Synthesis and stereochemical analysis of β-nitromethane substituted γ-amino acids and peptides.
Ganesh Kumar, Mothukuri; Mali, Sachitanand M.; Gopi, Hosahudya N.; Organic & biomolecular chemistry 11 (2013) 803–813; doi:10.1039/c2ob27070f

data_7152807
_publ_section_title
;
 Synthesis and stereochemical analysis of \b-nitromethane substituted
 \g-amino acids and peptides.
;
_journal_issue                   5
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              803
_journal_page_last               813
_journal_paper_doi               10.1039/c2ob27070f
_journal_volume                  11
_journal_year                    2013
_chemical_absolute_configuration syn
_chemical_compound_source        Synthesis
_chemical_formula_moiety         'C24 H44 N4 O9'
_chemical_formula_sum            'C24 H44 N4 O9'
_chemical_formula_weight         532.63
_chemical_name_systematic        Boc-gV(b-CH2NO2)-gL(b-CH2NO2)-COOEt
_space_group_IT_number           145
_symmetry_cell_setting           trigonal
_symmetry_Int_Tables_number      145
_symmetry_space_group_name_Hall  'P 32'
_symmetry_space_group_name_H-M   'P 32'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                120.00
_cell_formula_units_Z            3
_cell_length_a                   13.503(9)
_cell_length_b                   13.503(9)
_cell_length_c                   14.005(10)
_cell_measurement_temperature    100(2)
_cell_volume                     2211(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_pressure         101.325
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.974
_diffrn_measured_fraction_theta_max 0.974
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1857
_diffrn_reflns_av_sigmaI/netI    0.2766
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            14290
_diffrn_reflns_theta_full        29.54
_diffrn_reflns_theta_max         29.54
_diffrn_reflns_theta_min         1.74
_diffrn_source                   'fine-focus sealed tube'
_diffrn_source_type              'Graphite Monochromator'
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_T_max  0.984
_exptl_absorpt_correction_T_min  0.977
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.200
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'rod shapped'
_exptl_crystal_F_000             864
_exptl_crystal_recrystallization_method EtOAc
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.879
_refine_diff_density_min         -0.438
_refine_diff_density_rms         0.115
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -2(3)
_refine_ls_extinction_coef       0.014(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.873
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     343
_refine_ls_number_reflns         5572
_refine_ls_number_restraints     29
_refine_ls_restrained_S_all      0.878
_refine_ls_R_factor_all          0.2453
_refine_ls_R_factor_gt           0.0865
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1379P)^2^+0.6181P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2072
_refine_ls_wR_factor_ref         0.2952
_reflns_number_gt                1917
_reflns_number_total             5572
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob27070f.txt
_cod_data_source_block           P3
_cod_database_code               7152807