An efficient approach to functionalized benzo[a]xanthones through reactions of 2-methyl-3-(1-alkynyl)chromones with electron-deficient chromone-fused dienes.
Gong, Jian; Xie, Fuchun; Chen, Hong; Hu, Youhong; Organic letters 12 (2010) 3848–3851; doi:10.1021/ol101496w

data_1503135
_publ_section_title
;
 An efficient approach to functionalized benzo[a]xanthones through
 reactions of 2-methyl-3-(1-alkynyl)chromones with electron-deficient
 chromone-fused dienes.
;
_journal_issue                   17
_journal_name_full               'Organic letters'
_journal_page_first              3848
_journal_page_last               3851
_journal_paper_doi               10.1021/ol101496w
_journal_volume                  12
_journal_year                    2010
_chemical_formula_sum            'C36 H22 O4'
_chemical_formula_weight         518.54
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                70.157(4)
_cell_angle_beta                 78.535(4)
_cell_angle_gamma                70.146(4)
_cell_formula_units_Z            2
_cell_length_a                   9.799(2)
_cell_length_b                   11.072(2)
_cell_length_c                   13.689(3)
_cell_measurement_reflns_used    2346
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      53.297
_cell_measurement_theta_min      4.379
_cell_volume                     1308.1(5)
_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 0.983
_diffrn_measured_fraction_theta_max 0.983
_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  0.0338
_diffrn_reflns_av_sigmaI/netI    0.0453
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            7208
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         2.05
_exptl_absorpt_coefficient_mu    0.085
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.2446
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.316
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             540
_exptl_crystal_size_max          0.398
_exptl_crystal_size_mid          0.311
_exptl_crystal_size_min          0.247
_refine_diff_density_max         0.207
_refine_diff_density_min         -0.247
_refine_diff_density_rms         0.049
_refine_ls_extinction_coef       0.013(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.954
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     366
_refine_ls_number_reflns         5050
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.954
_refine_ls_R_factor_all          0.0740
_refine_ls_R_factor_gt           0.0568
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0929P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1458
_refine_ls_wR_factor_ref         0.1571
_reflns_number_gt                3558
_reflns_number_total             5050
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol101496w_si_001.cif
_cod_data_source_block           cd201230
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
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 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               1503135