Biomimetic Synthesis of Macahydantoins A and B from Lepidium meyenii, and Structure Revision of Macahydantoin B as a Class of Thiohydantoin with a 4-Methyl-hexahydropyrrolo[1,2-c]imidazole Skeleton.
Zhou, Min; Ma, Hang-Ying; Xing, Huan-Huan; Li, Ping; Li, Gan-Peng; Geng, Hui-Chun; Hu, Qiu-Fen; Yang, Guang-Yu; Organic letters 19 (2017) 4952–4955; doi:10.1021/acs.orglett.7b02433

data_1546977
_publ_section_title
;
 Biomimetic Synthesis of Macahydantoins A and B from Lepidium meyenii, and
 Structure Revision of Macahydantoin B as a Class of Thiohydantoin with a
 4-Methyl-hexahydropyrrolo[1,2-c]imidazole Skeleton.
;
_journal_issue                   18
_journal_name_full               'Organic letters'
_journal_page_first              4952
_journal_page_last               4955
_journal_paper_doi               10.1021/acs.orglett.7b02433
_journal_volume                  19
_journal_year                    2017
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C14 H16 N2 O S'
_chemical_formula_sum            'C14 H16 N2 O S'
_chemical_formula_weight         260.35
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.1830(7)
_cell_length_b                   11.5573(13)
_cell_length_c                   17.814(2)
_cell_measurement_reflns_used    3889
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      26.85
_cell_measurement_theta_min      2.29
_cell_volume                     1273.0(2)
_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      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.997
_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  0.0356
_diffrn_reflns_av_unetI/netI     0.0330
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.997
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            12659
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.997
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.146
_diffrn_reflns_theta_min         2.100
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.243
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.358
_exptl_crystal_description       prism
_exptl_crystal_F_000             552
_exptl_crystal_size_max          0.460
_exptl_crystal_size_mid          0.230
_exptl_crystal_size_min          0.100
_exptl_transmission_factor_max   0.4310
_exptl_transmission_factor_min   0.3807
_refine_diff_density_max         1.227
_refine_diff_density_min         -0.390
_refine_diff_density_rms         0.104
_refine_ls_abs_structure_details
;
 Flack x determined using 1020 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.03(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.057
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     163
_refine_ls_number_reflns         3118
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.057
_refine_ls_R_factor_all          0.0832
_refine_ls_R_factor_gt           0.0761
_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^)+(0.0899P)^2^+2.8812P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1882
_refine_ls_wR_factor_ref         0.1935
_reflns_Friedel_coverage         0.718
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.998
_reflns_number_gt                2809
_reflns_number_total             3118
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol7b02433_si_002.cif
_cod_data_source_block           mo_zm1_0m
_cod_depositor_comments          'Adding full bibliography for 1546977.cif.'
_cod_original_cell_volume        1273.0(3)
_cod_database_code               1546977
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.896
_shelx_estimated_absorpt_t_max   0.976
_shelx_res_checksum              46261
_shelx_hkl_checksum              8226