Synthetic Access to 3-Substituted Pyroglutamic Acids from Tetramate Derivatives of Serine, Threonine, <i>allo</i>-Threonine, and Cysteine.
Bagum, Halima; Christensen, Kirsten E.; Genov, Miroslav; Pretsch, Alexander; Pretsch, Dagmar; Moloney, Mark G.; The Journal of organic chemistry 84 (2019) 10257–10279; doi:10.1021/acs.joc.9b01432

data_4034002
_publ_section_title
;
 Synthetic Access to 3-Substituted Pyroglutamic Acids from Tetramate
 Derivatives of Serine, Threonine, <i>allo</i>-Threonine, and Cysteine.
;
_journal_issue                   16
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              10257
_journal_page_last               10279
_journal_paper_doi               10.1021/acs.joc.9b01432
_journal_volume                  84
_journal_year                    2019
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C19 H25 N1 O4'
_chemical_formula_sum            'C19 H25 N O4'
_chemical_formula_weight         331.41
_chemical_melting_point          ?
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     other
_audit_creation_date             2017-10-03
_audit_creation_method           CRYSTALS_ver_14.61_build_6566
_cell_angle_alpha                90
_cell_angle_beta                 90.9436(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.04850(10)
_cell_length_b                   20.7260(3)
_cell_length_c                   9.71100(10)
_cell_measurement_reflns_used    22718
_cell_measurement_temperature    150
_cell_measurement_theta_max      76
_cell_measurement_theta_min      4
_cell_volume                     1820.95(4)
_computing_cell_refinement       'CrysAlisPro, (Agilent, 2011)'
_computing_data_collection       'SuperNova, (Oxford Diffraction, 2010)'
_computing_data_reduction        'CrysAlisPro, (Agilent, 2011)'
_computing_molecular_graphics    'CAMERON (Watkin et al., 1996)'
_computing_publication_material  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_refinement  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_solution    'Superflip (Palatinus & Chapuis, 2007)'
_diffrn_ambient_temperature      150
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device       Area
_diffrn_measurement_device_type  'Oxford Diffraction SuperNova'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  'focussing mirrors'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.052
_diffrn_reflns_av_sigmaI/netI    0.0561
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            38515
_diffrn_reflns_theta_full        74.729
_diffrn_reflns_theta_max         76.254
_diffrn_reflns_theta_min         4.266
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.684
_exptl_absorpt_correction_T_max  0.90
_exptl_absorpt_correction_T_min  0.76
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrysAlisPro, (Agilent, 2011)'
_exptl_crystal_colour            clear_pale_colourless
_exptl_crystal_density_diffrn    1.209
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             711.994
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.21
_refine_diff_density_min         -0.19
_refine_ls_abs_structure_details
; 
 Parsons, Flack & Wagner (2013), 
 3314 Friedel Pairs 
;
_refine_ls_abs_structure_Flack   0.09(6)
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.0016
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     434
_refine_ls_number_reflns         7365
_refine_ls_number_restraints     1
_refine_ls_R_factor_all          0.0391
_refine_ls_R_factor_gt           0.0380
_refine_ls_shift/su_max          0.0003491
_refine_ls_shift/su_mean         0.0000434
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 Method= Modified Sheldrick 
 w=1/[\s^2^(F^2^) + ( 0.06P)^2^ + 0.28P] 
 ,where P=(max(Fo^2^,0) + 2Fc^2^)/3 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1011
_refine_ls_wR_factor_gt          0.0994
_refine_ls_wR_factor_ref         0.1011
_reflns_limit_h_max              11
_reflns_limit_h_min              -11
_reflns_limit_k_max              23
_reflns_limit_k_min              -25
_reflns_limit_l_max              12
_reflns_limit_l_min              0
_reflns_number_gt                7154
_reflns_number_total             7365
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   3.06
_oxford_diffrn_Wilson_scale      0.02
_oxford_refine_ls_r_factor_ref   0.0391
_oxford_refine_ls_scale          6.78(12)
_oxford_reflns_number_all        7365
_oxford_structure_analysis_title 6828
_cod_data_source_file            jo9b01432_si_002.cif
_cod_data_source_block           7cii
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_chemical_melting_point' value 'not measured' was changed
to '?' -- the value is undefined or not given.

data item '_exptl_crystal_density_meas' value 'not measured' was
changed to '?' -- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 6909 2019-04-08 15:41:33Z antanas 
;
_cod_original_sg_symbol_H-M      'P 21 '
_cod_original_formula_sum        'C19 H25 N1 O4'
_cod_database_code               4034002
_oxford_refine_reflns_threshold_expression_ref I>-10.0\s(I)
_oxford_hooft_y                  0.02(8)
_oxford_bijvoet_difference       0.09(6)
_oxford_refined_flack_x          0.02(12)