Metal-free, direct conversion of α-amino acids into α-keto γ-amino esters for the syntesis of α,γ-Peptides
HERNÁNDEZ MESA, DÁCIL; Boto, Alicia; Guzman, David; Alvarez González, Eleuterio; Org. Biomol. Chem.  (2017) –; doi:10.1039/C7OB02033C

data_7155847
_publ_section_title
;
 Metal-free, direct conversion of \a-amino acids into \a-keto \g-amino
 esters for the syntesis of \a,\g-Peptides
;
_journal_name_full               'Org. Biomol. Chem.'
_journal_paper_doi               10.1039/C7OB02033C
_journal_year                    2017
_chemical_absolute_configuration rm
_chemical_formula_moiety         'C25 H30 N2 O6'
_chemical_formula_sum            'C25 H30 N2 O6'
_chemical_formula_weight         454.51
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2016/6
_audit_update_record
;
2017-04-30 deposited with the CCDC.
2017-08-22 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 98.151(4)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   14.6880(15)
_cell_length_b                   5.0342(5)
_cell_length_c                   16.7218(15)
_cell_measurement_reflns_used    3412
_cell_measurement_temperature    193(2)
_cell_measurement_theta_max      24.71
_cell_measurement_theta_min      3.46
_cell_volume                     1224.0(2)
_computing_cell_refinement       'APEX2 Software Suite (Bruker, 2007)'
_computing_data_collection       'APEX2 Software Suite (Bruker, 2007)'
_computing_data_reduction        'APEX2 Software Suite (Bruker, 2007)'
_computing_molecular_graphics    'SHELXTL (Sheldrick, 2008)'
_computing_publication_material  'SHELXTL and publCIF (Westrip, 2010)'
_computing_structure_refinement  'SHELXL-2016/6 (Sheldrick, 2016)'
_computing_structure_solution    'SIR2002 (Burla et al., 2003)'
_diffrn_ambient_temperature      193(2)
_diffrn_detector_area_resol_mean 8.26
_diffrn_measured_fraction_theta_full 0.882
_diffrn_measured_fraction_theta_max 0.882
_diffrn_measurement_device_type
;
 Bruker-Nonius X8kappa APEX II CCD area detector
;
_diffrn_measurement_method       'phi and omega scans with narrow frames'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0398
_diffrn_reflns_av_unetI/netI     0.0359
_diffrn_reflns_Laue_measured_fraction_full 0.882
_diffrn_reflns_Laue_measured_fraction_max 0.882
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            12797
_diffrn_reflns_point_group_measured_fraction_full 0.713
_diffrn_reflns_point_group_measured_fraction_max 0.712
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.249
_diffrn_reflns_theta_min         3.216
_exptl_absorpt_coefficient_mu    0.088
_exptl_absorpt_correction_T_max  0.9912
_exptl_absorpt_correction_T_min  0.9572
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
program SADABS, Bruker (2001).
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.233
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             484
_exptl_crystal_size_max          0.500
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.303
_refine_diff_density_min         -0.218
_refine_diff_density_rms         0.051
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     307
_refine_ls_number_reflns         3145
_refine_ls_number_restraints     87
_refine_ls_restrained_S_all      1.014
_refine_ls_R_factor_all          0.0679
_refine_ls_R_factor_gt           0.0523
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1031P)^2^+0.0690P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1348
_refine_ls_wR_factor_ref         0.1444
_reflns_Friedel_coverage         0.437
_reflns_Friedel_fraction_full    0.495
_reflns_Friedel_fraction_max     0.494
_reflns_number_gt                2575
_reflns_number_total             3145
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c7ob02033c2.cif
_cod_data_source_block           42
_cod_database_code               7155847
_shelx_shelxl_version_number     2016/6
_shelx_estimated_absorpt_t_min   0.957
_shelx_estimated_absorpt_t_max   0.991
_shelx_res_checksum              53040