Bis-lactim ethers of cyclic dipeptides. 2. Benzyl-substituted compounds
Bolte, Michael; Benecke, Bernd; Egert, Ernst; Acta Crystallographica Section C 55 (1999) 968–973; doi:10.1107/S010827019801645X

data_2008639
_publ_section_title
;
 Bis-lactim ethers of cyclic dipeptides. 2. Benzyl-substituted
 compounds
;
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              968
_journal_page_last               973
_journal_paper_doi               10.1107/S010827019801645X
_journal_volume                  55
_journal_year                    1999
_chemical_formula_sum            'C20 H22 N2 O2'
_chemical_formula_weight         322.40
_chemical_name_systematic
;
(3S,6S)-3,6-Dibenzyl-2,5-dimethoxy-3,6-dihydro-pyrazine
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_audit_creation_method           SHELXL
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_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.9980(10)
_cell_length_b                   11.5130(10)
_cell_length_c                   14.4640(10)
_cell_measurement_reflns_used    48
_cell_measurement_temperature    293
_cell_measurement_theta_max      15
_cell_measurement_theta_min      10
_cell_volume                     1831.4(3)
_computing_cell_refinement       D4
_computing_data_collection       'D4 (Clegg, 1981)'
_computing_data_reduction        'REDU4 (Stoe & Cie, 1988)'
_computing_molecular_graphics    'XP (Sheldrick, 1991)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1985)'
_diffrn_ambient_temperature      293
_diffrn_measurement_device       'Stoe Siemens four-circle diffractometer'
_diffrn_measurement_method       '\w-\q scans with learnt profile (Clegg, 1981)'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0244
_diffrn_reflns_limit_h_max       0
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            1840
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         3.54
_diffrn_standards_decay_%        4
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.076
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.169
_exptl_crystal_description       block
_exptl_crystal_F_000             688
_exptl_crystal_size_max          0.6
_exptl_crystal_size_mid          0.4
_exptl_crystal_size_min          0.4
_refine_diff_density_max         0.124
_refine_diff_density_min         -0.107
_refine_ls_extinction_coef       0.019(2)
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 1997)'
_refine_ls_goodness_of_fit_all   1.080
_refine_ls_goodness_of_fit_obs   1.121
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     218
_refine_ls_number_reflns         1840
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.080
_refine_ls_restrained_S_obs      1.121
_refine_ls_R_factor_all          0.0514
_refine_ls_R_factor_obs          .0418
_refine_ls_shift/esd_max         0.000
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0432P)^2^+0.3472P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1032
_refine_ls_wR_factor_obs         .0971
_reflns_number_observed          1548
_reflns_number_total             1840
_reflns_observed_criterion       I>2\s(I)
_cod_data_source_file            sk1255.cif
_cod_data_source_block           II
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.0432P)^2^+0.3472P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w =
1/[\s^2^(Fo^2^)+(0.0432P)^2^+0.3472P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_database_code               2008639
_cod_database_fobs_code          2008639