Pyridine-catalyzed addition of diaryl-1,2-diones to dimethyl butynedioate leading to the formation of 1,2-diaroyl dimethyl maleates via an unprecedented rearrangement.
Nair, Vijay; Pillai, Abhilash N.; Menon, Rajeev S.; Suresh, Eringathodi; Organic letters 7 (2005) 1189–1191; doi:10.1021/ol050225k

data_1506540
_publ_section_title
;
 Pyridine-catalyzed addition of diaryl-1,2-diones to dimethyl butynedioate
 leading to the formation of 1,2-diaroyl dimethyl maleates via an
 unprecedented rearrangement.
;
_journal_issue                   6
_journal_name_full               'Organic letters'
_journal_page_first              1189
_journal_page_last               1191
_journal_paper_doi               10.1021/ol050225k
_journal_volume                  7
_journal_year                    2005
_chemical_formula_sum            'C20 H16 O6'
_chemical_formula_weight         352.33
_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'
_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                 100.433(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
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_cell_length_b                   14.888(2)
_cell_length_c                   14.573(2)
_cell_measurement_temperature    296(2)
_cell_volume                     1715.3(4)
_computing_cell_refinement       BRUKER_SMART
_computing_data_collection       BRUKER_SMART
_computing_data_reduction        BRUKER_SAINT
_computing_molecular_graphics    'ORTEP, PLATON'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.835
_diffrn_measured_fraction_theta_max 0.835
_diffrn_measurement_device_type  'SMART APEX CCD DIFFRACTOMETER'
_diffrn_measurement_method       'OMEGA SACN'
_diffrn_radiation_monochromator  graphite
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_diffrn_reflns_limit_h_max       10
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_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            8676
_diffrn_reflns_theta_full        28.33
_diffrn_reflns_theta_max         28.33
_diffrn_reflns_theta_min         1.97
_exptl_absorpt_coefficient_mu    0.101
_exptl_absorpt_correction_type   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.364
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       blocks
_exptl_crystal_F_000             736
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.16
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_refine_ls_extinction_method     none
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_refine_ls_number_reflns         3715
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_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0812P)^2^+0.6303P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1674
_refine_ls_wR_factor_ref         0.1886
_reflns_number_gt                2650
_reflns_number_total             3715
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol050225ksi20050203_045553.cif
_cod_data_source_block           vijay1m(ABN-II)
_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_values 1715 2011-07-08 13:25:40Z adriana 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0812P)^2^+0.6303P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0812P)^2^+0.6303P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_sg_symbol_H-M      P_21/c
_cod_database_code               1506540