DABCO and Bu3P catalyzed [4 + 2] and [3 + 2] cycloadditions of 3-acyl-2H-chromen-ones and ethyl 2,3-butadienoate.
Wang, Ying; Yu, Zhi-Hua; Zheng, Hu-Fei; Shi, De-Qing; Organic & biomolecular chemistry 10 (2012) 7739–7746; doi:10.1039/c2ob26300a

data_7152681
_publ_section_title
;
 DABCO and Bu3P catalyzed [4 + 2] and [3 + 2] cycloadditions of
 3-acyl-2H-chromen-ones and ethyl 2,3-butadienoate.
;
_journal_issue                   38
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              7739
_journal_page_last               7746
_journal_paper_doi               10.1039/c2ob26300a
_journal_volume                  10
_journal_year                    2012
_chemical_formula_sum            'C22 H17 Br O5'
_chemical_formula_weight         441.27
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 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                   11.756
_cell_length_b                   14.575
_cell_length_c                   11.520
_cell_measurement_reflns_used    2202
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      18.98
_cell_measurement_theta_min      2.23
_cell_volume                     1973.879
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_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 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w 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  0.0520
_diffrn_reflns_av_sigmaI/netI    0.0729
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            14075
_diffrn_reflns_theta_full        26.48
_diffrn_reflns_theta_max         26.48
_diffrn_reflns_theta_min         2.23
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.113
_exptl_absorpt_correction_T_max  0.8165
_exptl_absorpt_correction_T_min  0.6673
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS, Sheldrick,1997'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.485
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             896
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.220
_refine_diff_density_min         -0.211
_refine_diff_density_rms         0.044
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.009(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.986
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     271
_refine_ls_number_reflns         3918
_refine_ls_number_restraints     9
_refine_ls_restrained_S_all      1.006
_refine_ls_R_factor_all          0.0920
_refine_ls_R_factor_gt           0.0394
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0310P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0809
_refine_ls_wR_factor_ref         0.0971
_reflns_number_gt                2297
_reflns_number_total             3918
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob26300a.txt
_cod_data_source_block           I
_cod_depositor_comments
;
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_cell_volume        1973.9
_cod_original_sg_symbol_H-M      Pna2(1)
_cod_database_code               7152681