Cascade reaction of β,γ-unsaturated α-ketoesters with phenols in trityl chloride/TFA system. Highly selective synthesis of 4-aryl-2H-chromenes and their applications.
Wu, Yan-Chao; Li, Hui-Jing; Liu, Li; Liu, Zhe; Wang, Dong; Chen, Yong-Jun; Organic & biomolecular chemistry 9 (2011) 2868–2877; doi:10.1039/c0ob01143f

data_7151820
_publ_section_title
;
 Cascade reaction of \b,\g-unsaturated \a-ketoesters with phenols in
 trityl chloride/TFA system. Highly selective synthesis of
 4-aryl-2H-chromenes and their applications.
;
_journal_issue                   8
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              2868
_journal_page_last               2877
_journal_paper_doi               10.1039/c0ob01143f
_journal_volume                  9
_journal_year                    2011
_chemical_formula_sum            'C21 H22 O3'
_chemical_formula_weight         322.39
_space_group_IT_number           9
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C -2yc'
_symmetry_space_group_name_H-M   'C 1 c 1'
_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                 114.81(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   17.683(4)
_cell_length_b                   10.819(2)
_cell_length_c                   10.206(2)
_cell_measurement_reflns_used    6608
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      2.54
_cell_volume                     1772.3(8)
_computing_cell_refinement       'Rapid Auto(Rigaku 2001)'
_computing_data_collection       'Rapid Auto(Rigaku 2001)'
_computing_data_reduction        'Rapid Auto(Rigaku 2001)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.980
_diffrn_measured_fraction_theta_max 0.980
_diffrn_measurement_device_type  'Rigaku Raxis Rapid IP'
_diffrn_measurement_method       oscillation
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Rotating Anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0799
_diffrn_reflns_av_sigmaI/netI    0.0706
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            6608
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         2.54
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_T_max  0.9881
_exptl_absorpt_correction_T_min  0.9551
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   abscor
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.208
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             688
_exptl_crystal_size_max          0.58
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.307
_refine_diff_density_min         -0.303
_refine_diff_density_rms         0.055
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   1(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.017
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         1990
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.017
_refine_ls_R_factor_all          0.0905
_refine_ls_R_factor_gt           0.0698
_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^)+(0.1002P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1715
_refine_ls_wR_factor_ref         0.1823
_reflns_number_gt                1363
_reflns_number_total             1990
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c0ob01143f.txt
_cod_data_source_block           13a
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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 1555 2011-01-17 13:19:09Z saulius 
;
_cod_original_cell_volume        1772.3(6)
_cod_original_sg_symbol_H-M      Cc
_cod_database_code               7151820