A base-promoted desalicyloylative dimerization of 3-(1-alkynyl)chromones: an unusual approach to 2-alkynyl xanthones.
Xie, Fuchun; Pan, Xuan; Lin, Shijun; Hu, Youhong; Organic & biomolecular chemistry 8 (2010) 1378–1381; doi:10.1039/b925234g

data_7153310
_publ_section_title
;
 A base-promoted desalicyloylative dimerization of 3-(1-alkynyl)chromones:
 an unusual approach to 2-alkynyl xanthones.
;
_journal_issue                   6
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1378
_journal_page_last               1381
_journal_paper_doi               10.1039/b925234g
_journal_volume                  8
_journal_year                    2010
_chemical_absolute_configuration unknown
_chemical_formula_sum            'C29 H20 O4'
_chemical_formula_weight         432.45
_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                   6.3113(6)
_cell_length_b                   8.5733(9)
_cell_length_c                   39.914(4)
_cell_measurement_reflns_used    2069
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      42.579
_cell_measurement_theta_min      4.860
_cell_volume                     2159.7(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0593
_diffrn_reflns_av_sigmaI/netI    0.0540
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       49
_diffrn_reflns_limit_l_min       -44
_diffrn_reflns_number            11925
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.04
_exptl_absorpt_coefficient_mu    0.088
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.8109
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            green
_exptl_crystal_density_diffrn    1.330
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             904
_exptl_crystal_size_max          0.307
_exptl_crystal_size_mid          0.215
_exptl_crystal_size_min          0.076
_refine_diff_density_max         0.130
_refine_diff_density_min         -0.125
_refine_diff_density_rms         0.027
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   10(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.832
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     300
_refine_ls_number_reflns         2469
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.832
_refine_ls_R_factor_all          0.0547
_refine_ls_R_factor_gt           0.0334
_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^)+(0.0251P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0587
_refine_ls_wR_factor_ref         0.0623
_reflns_number_gt                1640
_reflns_number_total             2469
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b925234g.txt
_cod_data_source_block           cd29355
_cod_depositor_comments
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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 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7153310