Structures of oxygenated cyclohexa-1,3-diene-maleic anyhydride cycloadducts. Structural evidence suggests a stepwise retro-Diels-Alder reaction.
Goh, Yit Wooi; White, Jonathan M.; Organic & biomolecular chemistry 5 (2007) 2354–2356; doi:10.1039/b707643f

data_7151141
_publ_section_title
;
 Structures of oxygenated cyclohexa-1,3-diene-maleic anyhydride
 cycloadducts. Structural evidence suggests a stepwise
 retro-Diels-Alder reaction.
;
_journal_issue                   15
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              2354
_journal_page_last               2356
_journal_paper_doi               10.1039/b707643f
_journal_volume                  5
_journal_year                    2007
_chemical_formula_sum            'C11 H12 O4'
_chemical_formula_weight         208.21
_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                 99.149(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.9224(7)
_cell_length_b                   13.7063(14)
_cell_length_c                   10.2746(10)
_cell_measurement_reflns_used    1848
_cell_measurement_temperature    130(2)
_cell_measurement_theta_max      26.92
_cell_measurement_theta_min      2.97
_cell_volume                     962.46(17)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      130(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_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  0.0394
_diffrn_reflns_av_sigmaI/netI    0.0410
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            4983
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.50
_exptl_absorpt_coefficient_mu    0.110
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.437
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             440
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.241
_refine_diff_density_min         -0.165
_refine_diff_density_rms         0.038
_refine_ls_extinction_coef       0.008(3)
_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   0.984
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     138
_refine_ls_number_reflns         1699
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.984
_refine_ls_R_factor_all          0.0449
_refine_ls_R_factor_gt           0.0364
_refine_ls_shift/su_max          0.012
_refine_ls_shift/su_mean         0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0544P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0905
_refine_ls_wR_factor_ref         0.0936
_reflns_number_gt                1398
_reflns_number_total             1699
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b707643f.txt
_cod_data_source_block           jmwrg122
_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 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      'P2(1)/c '
_cod_database_code               7151141