Natural Product-Derived Chiral Pyrrolidine-2,5-diones, Their Molecular Structures and Conversion to Pharmacologically Important Skeletons.
Habel, Deenamma; Nair, Divya S.; Kallingathodi, Zabeera; Mohan, Chithra; Pillai, Sarath M.; Nair, Rani R.; Thomas, Grace; Haleema, Simimole; Gopinath, Chithra; Abdul, Rinshad V.; Fritz, Matthew; Puente, Andrew R.; Johnson, Jordan L.; Polavarapu, Prasad L.; Ibnusaud, Ibrahim; Journal of natural products  (2020) –; doi:10.1021/acs.jnatprod.0c00211

data_1558432
_publ_section_title
;
 Natural Product-Derived Chiral Pyrrolidine-2,5-diones, Their Molecular
 Structures and Conversion to Pharmacologically Important Skeletons.
;
_journal_name_full               'Journal of natural products'
_journal_paper_doi               10.1021/acs.jnatprod.0c00211
_journal_year                    2020
_chemical_formula_sum            'C16 H18 N2 O4'
_chemical_formula_weight         302.32
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 93.200(3)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   5.6660(3)
_cell_length_b                   9.3371(7)
_cell_length_c                   12.7013(9)
_cell_measurement_reflns_used    3239
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      27.23
_cell_measurement_theta_min      2.71
_cell_volume                     670.90(8)
_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-2014 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      296(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_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0213
_diffrn_reflns_av_unetI/netI     0.0259
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            5256
_diffrn_reflns_point_group_measured_fraction_full 0.878
_diffrn_reflns_point_group_measured_fraction_max 0.878
_diffrn_reflns_theta_full        24.985
_diffrn_reflns_theta_max         24.985
_diffrn_reflns_theta_min         1.606
_exptl_absorpt_coefficient_mu    0.109
_exptl_absorpt_correction_T_max  0.97
_exptl_absorpt_correction_T_min  0.96
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Bruker, 2012)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.497
_exptl_crystal_description       Rectangular
_exptl_crystal_F_000             320
_exptl_crystal_size_max          0.350
_exptl_crystal_size_mid          0.260
_exptl_crystal_size_min          0.120
_refine_diff_density_max         0.365
_refine_diff_density_min         -0.223
_refine_diff_density_rms         0.063
_refine_ls_abs_structure_details
;
 Flack x determined using 751 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.6(4)
_refine_ls_extinction_coef       0.030(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.173
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     210
_refine_ls_number_reflns         2072
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.173
_refine_ls_R_factor_all          0.0490
_refine_ls_R_factor_gt           0.0472
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0628P)^2^+0.7818P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1390
_refine_ls_wR_factor_ref         0.1404
_reflns_Friedel_coverage         0.652
_reflns_Friedel_fraction_full    0.744
_reflns_Friedel_fraction_max     0.744
_reflns_number_gt                1990
_reflns_number_total             2072
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            np0c00211_si_006.cif
_cod_data_source_block           gatrrn
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               1558432
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.963
_shelx_estimated_absorpt_t_max   0.987
_shelx_res_checksum              14919
_shelx_hkl_checksum              47376