Pregna-1,4,9(11),16-tetraene-3,20-dione
Zhang, Guo-Lin; Peng, Hong-Yun; Acta Crystallographica Section E 62 (2006) o5534–o5535; doi:10.1107/S1600536806046514

data_2211670
_publ_section_title
;
 Pregna-1,4,9(11),16-tetraene-3,20-dione
;
_journal_coeditor_code           XU2130
_journal_issue                   12
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o5534
_journal_page_last               o5535
_journal_paper_doi               10.1107/S1600536806046514
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C21 H24 O2'
_chemical_formula_moiety         'C21 H24 O2'
_chemical_formula_sum            'C21 H24 O2'
_chemical_formula_weight         308.40
_chemical_name_systematic
;
Pregna-1,4,9(11),16-tetraene-3,20-dione
;
_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'
_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                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.6433(19)
_cell_length_b                   11.278(4)
_cell_length_c                   22.951(8)
_cell_measurement_reflns_used    12671
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3.2
_cell_volume                     1719.6(10)
_computing_cell_refinement       PROCESS-AUTO
_computing_data_collection       'PROCESS-AUTO (Rigaku, 1998)'
_computing_data_reduction        'CrystalStructure (Rigaku/MSC, 2004)'
_computing_molecular_graphics    'ORTEP-3 for Windows (Farrugia,1997)'
_computing_publication_material  'WinGX (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Altomare <i>et al.</i>,  1999)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 10.00
_diffrn_measured_fraction_theta_full 1.00
_diffrn_measured_fraction_theta_max 1.00
_diffrn_measurement_device_type  'Rigaku R-AXIS RAPID'
_diffrn_measurement_method       \w
_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  0.036
_diffrn_reflns_av_sigmaI/netI    0.021
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            17000
_diffrn_reflns_theta_full        27.4
_diffrn_reflns_theta_max         27.4
_diffrn_reflns_theta_min         3.1
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.075
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.191
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       chunk
_exptl_crystal_F_000             664
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.36
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.14
_refine_diff_density_min         -0.15
_refine_ls_extinction_coef       0.026(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.110
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     212
_refine_ls_number_reflns         2267
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.110
_refine_ls_R_factor_all          0.073
_refine_ls_R_factor_gt           0.039
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.055P)^2^+0.1715P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.097
_refine_ls_wR_factor_ref         0.124
_reflns_number_gt                1393
_reflns_number_total             2267
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            xu2130.cif
_cod_data_source_block           I
_cod_database_code               2211670
_cod_database_fobs_code          2211670