(–)-Isosantonic acid: alteration of the hydrogen-bonding mode by configurational inversion at a single centre in a γ,ε-diketocarboxylic acid
Zinczuk, Juan; Ruveda, Edmundo A.; Lalancette, Roger A.; Thompson, Hugh W.; Acta Crystallographica Section E 62 (2006) o2120–o2122; doi:10.1107/S160053680601405X

data_2209239
_publ_section_title
;
 (--)-Isosantonic acid: alteration of the hydrogen-bonding mode by
 configurational inversion at a single centre in a
 \g,\e-diketocarboxylic acid
;
_journal_coeditor_code           LH2039
_journal_issue                   6
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2120
_journal_page_last               o2122
_journal_paper_doi               10.1107/S160053680601405X
_journal_volume                  62
_journal_year                    2006
_chemical_formula_iupac          'C15 H20 O4'
_chemical_formula_moiety         'C15 H20 O4'
_chemical_formula_sum            'C15 H20 O4'
_chemical_formula_weight         264.31
_chemical_melting_point          424
_chemical_name_common            '(-)-isosantonic acid'
_chemical_name_systematic
;
(1R,3aS,6aS,7R,9S)-(-)-\a,3a,7-trimethyl-5,8-dioxo-1,4-
ethanoperhydropentalene-1-acetic acid'
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.3801(2)
_cell_length_b                   12.5398(2)
_cell_length_c                   12.6852(2)
_cell_measurement_reflns_used    7889
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      68.3
_cell_measurement_theta_min      3.48
_cell_volume                     1333.02(4)
_computing_cell_refinement       SMART
_computing_data_collection       'SMART (Bruker, 2000)'
_computing_data_reduction        'SAINT-Plus (Bruker, 2000)'
_computing_molecular_graphics    'SHELXTL (Bruker, 2000)'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.971
_diffrn_measured_fraction_theta_max 0.944
_diffrn_measurement_device_type  'Bruker SMART CCD area-detector'
_diffrn_measurement_method       '\f and \w'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.017
_diffrn_reflns_av_sigmaI/netI    0.008
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            15403
_diffrn_reflns_theta_full        69.24
_diffrn_reflns_theta_max         69.24
_diffrn_reflns_theta_min         4.96
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.773
_exptl_absorpt_correction_T_max  0.820
_exptl_absorpt_correction_T_min  0.750
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Blessing, 1995)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.317
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             568
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.34
_exptl_crystal_size_min          0.26
_refine_diff_density_max         0.21
_refine_diff_density_min         -0.16
_refine_ls_abs_structure_details 'Flack (1983), with 950 Friedel pairs'
_refine_ls_abs_structure_Flack   0.02(15)
_refine_ls_extinction_coef       0.0065(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 1997)'
_refine_ls_goodness_of_fit_ref   0.979
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     253
_refine_ls_number_reflns         2321
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.98
_refine_ls_R_factor_all          0.025
_refine_ls_R_factor_gt           0.025
_refine_ls_shift/su_max          0.00
_refine_ls_shift/su_mean         0.00
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0435P)^2^+0.3883P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.066
_refine_ls_wR_factor_ref         0.066
_reflns_number_gt                2320
_reflns_number_total             2321
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            lh2039.cif
_cod_data_source_block           I
_cod_database_code               2209239
_cod_database_fobs_code          2209239