Racemic 3-(3,4-dimethoxyphenyl)-5a,6,8,9-tetrahydro-1<i>H</i>,7<i>H</i>-pyrano[4,3-<i>b</i>][1]benzopyran-1-one, an active antitumor agent
Robinson, Paul D.; Beatty, Alicia; Hua, Duy H.; Chen, Yi; Meyers, Cal Y.; Perchellet, Elisabeth M.; Ladesich, James B.; Perchellet, Jean-Pierre; Acta Crystallographica Section C 55 (1999) 1188–1190; doi:10.1107/S0108270199003315

data_2008740
_publ_section_title
;Racemic
 3-(3,4-dimethoxyphenyl)-5a,6,8,9-tetrahydro-1<i>H</i>,7<i>H</i>-pyrano[4,3-<i>b</i>][1]benzopyran-1-one,
 an active antitumor agent
;
_journal_issue                   7
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1188
_journal_page_last               1190
_journal_paper_doi               10.1107/S0108270199003315
_journal_volume                  55
_journal_year                    1999
_chemical_formula_moiety         'C20 H20 O5'
_chemical_formula_sum            'C20 H20 O5'
_chemical_formula_weight         340.36
_chemical_name_systematic
;
3-(3,4-dimethoxyphenyl)-5a,6,8,9-tetrahydro-1H,7H-
pyrano[4,3-b][1]benzopyran-1-one
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_cell_angle_alpha                90.00
_cell_angle_beta                 94.453(8)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.1017(12)
_cell_length_b                   22.918(4)
_cell_length_c                   8.9358(11)
_cell_measurement_reflns_used    30
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      12.43
_cell_measurement_theta_min      5.14
_cell_volume                     1654.1(4)
_computing_cell_refinement       XSCANS
_computing_data_collection       'XSCANS (Siemens, 1994)'
_computing_data_reduction
'TEXSAN (Molecular Structure Corporation, 1997)'
_computing_molecular_graphics    'ORTEP (Johnson, 1965) and PLATON (Spek, 1990)'
_computing_publication_material  'TEXSAN, SHELXL97, and PLATON'
_computing_structure_refinement  'TEXSAN and SHELXL97'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device       'Siemens P4'
_diffrn_measurement_method       '2\q/\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.016
_diffrn_reflns_av_sigmaI/netI    0.019
_diffrn_reflns_limit_h_max       1
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       1
_diffrn_reflns_limit_k_min       -27
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            3171
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25
_diffrn_reflns_theta_min         2.45
_diffrn_standards_decay_%        2.1
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.098
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            orange
_exptl_crystal_density_diffrn    1.367
_exptl_crystal_density_meas      ?
_exptl_crystal_description       prism
_exptl_crystal_F_000             720
_exptl_crystal_size_max          0.6
_exptl_crystal_size_mid          0.5
_exptl_crystal_size_min          0.4
_refine_diff_density_max         0.270
_refine_diff_density_min         -0.151
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.056
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     274
_refine_ls_number_reflns         2915
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.056
_refine_ls_R_factor_all          0.073
_refine_ls_R_factor_gt           0.054
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0716P)^2^+0.6728P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.150
_reflns_number_gt                2249
_reflns_number_total             2915
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sx1082.cif
_cod_data_source_block           default
_cod_depositor_comments
;
The following automatic conversions were performed:

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

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               2008740