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_4034001
_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         'C18 H23 N O4'
_chemical_formula_sum            'C18 H23 N O4'
_chemical_formula_weight         317.38
_chemical_melting_point          ?
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     other
_audit_creation_date             2017-09-11
_audit_creation_method           CRYSTALS_ver_14.61_build_6320
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.50220(10)
_cell_length_b                   9.57370(10)
_cell_length_c                   21.0075(3)
_cell_measurement_reflns_used    8804
_cell_measurement_temperature    150
_cell_measurement_theta_max      76
_cell_measurement_theta_min      4
_cell_volume                     1709.96(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 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device       Area
_diffrn_measurement_device_type  'Oxford Diffraction SuperNova'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.036
_diffrn_reflns_av_sigmaI/netI    0.0404
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            13518
_diffrn_reflns_theta_full        76.128
_diffrn_reflns_theta_max         76.128
_diffrn_reflns_theta_min         4.209
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.707
_exptl_absorpt_correction_T_max  0.97
_exptl_absorpt_correction_T_min  0.75
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrysAlisPro, (Agilent, 2011)'
_exptl_crystal_colour            clear_pale_colourless
_exptl_crystal_density_diffrn    1.233
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             680
_exptl_crystal_size_max          0.31
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.18
_refine_diff_density_min         -0.17
_refine_ls_abs_structure_details 'Flack (1983), 1487 Friedel-pairs'
_refine_ls_abs_structure_Flack   0.14(15)
_refine_ls_extinction_coef       53(8)
_refine_ls_extinction_method     'Larson (1970), Equation 22'
_refine_ls_goodness_of_fit_ref   1.0054
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     210
_refine_ls_number_reflns         3535
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0347
_refine_ls_R_factor_gt           0.0339
_refine_ls_shift/su_max          0.0008060
_refine_ls_shift/su_mean         0.0000680
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 Method= Modified Sheldrick 
 w=1/[\s^2^(F^2^) + ( 0.07P)^2^ + 0.13P] 
 ,where P=(max(Fo^2^,0) + 2Fc^2^)/3 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0923
_refine_ls_wR_factor_gt          0.0907
_refine_ls_wR_factor_ref         0.0923
_reflns_limit_h_max              10
_reflns_limit_h_min              -10
_reflns_limit_k_max              11
_reflns_limit_k_min              0
_reflns_limit_l_max              26
_reflns_limit_l_min              0
_reflns_number_gt                3433
_reflns_number_total             3535
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   3.01
_oxford_diffrn_Wilson_scale      0.02
_oxford_refine_ls_r_factor_ref   0.0347
_oxford_refine_ls_scale          7.5(2)
_oxford_reflns_number_all        3535
_oxford_reflns_threshold_expression_ref I>-10.0\s(I)
_oxford_structure_analysis_title 6810
_cod_data_source_file            jo9b01432_si_002.cif
_cod_data_source_block           7aii
_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 '_atom_sites_solution_primary' value 'Other' was changed to
'other' in accordance with the
/home/data/users/saulius/crontab/automatic-downloads/current/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

Automatic conversion script
Id: cif_fix_values 6909 2019-04-08 15:41:33Z antanas 
;
_cod_original_sg_symbol_H-M      'P 21 21 21 '
_cod_database_code               4034001