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_1558433
_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_moiety         'C17.50 H18 N2 O4'
_chemical_formula_sum            'C17.5 H18 N2 O4'
_chemical_formula_weight         320.34
_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                 92.854(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   16.8725(6)
_cell_length_b                   5.1182(2)
_cell_length_c                   17.3866(6)
_cell_measurement_reflns_used    4096
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      23.42
_cell_measurement_theta_min      2.35
_cell_volume                     1499.59(9)
_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-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_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  0.0242
_diffrn_reflns_av_unetI/netI     0.0395
_diffrn_reflns_Laue_measured_fraction_full 0.993
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            11530
_diffrn_reflns_point_group_measured_fraction_full 0.948
_diffrn_reflns_point_group_measured_fraction_max 0.948
_diffrn_reflns_theta_full        24.995
_diffrn_reflns_theta_max         24.995
_diffrn_reflns_theta_min         1.208
_exptl_absorpt_coefficient_mu    0.102
_exptl_absorpt_correction_T_max  0.988
_exptl_absorpt_correction_T_min  0.975
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2014/5(Bruker AXS.Inc)'
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.419
_exptl_crystal_description       Rectangular
_exptl_crystal_F_000             676
_exptl_crystal_size_max          0.250
_exptl_crystal_size_mid          0.220
_exptl_crystal_size_min          0.120
_refine_diff_density_max         0.144
_refine_diff_density_min         -0.372
_refine_diff_density_rms         0.044
_refine_ls_abs_structure_details
; 
 Flack x determined using 1485 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.7(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.060
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     421
_refine_ls_number_reflns         4990
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.060
_refine_ls_R_factor_all          0.0579
_refine_ls_R_factor_gt           0.0445
_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^)+(0.0644P)^2^+0.4227P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1169
_refine_ls_wR_factor_ref         0.1256
_reflns_Friedel_coverage         0.699
_reflns_Friedel_fraction_full    0.890
_reflns_Friedel_fraction_max     0.890
_reflns_number_gt                4165
_reflns_number_total             4990
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            np0c00211_si_007.cif
_cod_data_source_block           hat
_cod_original_sg_symbol_H-M      'P 21'
_cod_original_formula_sum        'C17.50 H18 N2 O4'
_cod_database_code               1558433
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.975
_shelx_estimated_absorpt_t_max   0.988
_shelx_res_checksum              96923
_shelx_hkl_checksum              99612