Asymmetric synthesis of the tetracyclic core of bufogargarizin C by an intramolecular [5 + 2] cycloaddition
Fan, Jian-Hong; Hu, Ya-Jian; Guo, Qiang; Li, Shaoping; Zhao, Jing; Li, Chuang-Chuang; Organic Chemistry Frontiers 6 (2019) 22–; doi:10.1039/C8QO01089G

data_1554498
_publ_section_title
;
 Asymmetric synthesis of the tetracyclic core of bufogargarizin C by an
 intramolecular [5 + 2] cycloaddition
;
_journal_issue                   1
_journal_name_full               'Organic Chemistry Frontiers'
_journal_page_first              22
_journal_paper_doi               10.1039/C8QO01089G
_journal_volume                  6
_journal_year                    2019
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C38 H42 Cl2 O7'
_chemical_formula_sum            'C38 H42 Cl2 O7'
_chemical_formula_weight         681.61
_space_group_crystal_system      monoclinic
_space_group_IT_number           5
_space_group_name_Hall           'C 2y'
_space_group_name_H-M_alt        'C 1 2 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2018-07-17
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_audit_update_record
;
2018-09-14 deposited with the CCDC.
2018-11-05 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 105.306(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   25.2058(19)
_cell_length_b                   7.2704(6)
_cell_length_c                   19.2306(15)
_cell_measurement_reflns_used    9841
_cell_measurement_temperature    100
_cell_measurement_theta_max      27.63
_cell_measurement_theta_min      2.38
_cell_volume                     3399.1(5)
_computing_cell_refinement       'SAINT v8.37A (Bruker, 2015)'
_computing_data_reduction        'SAINT v8.37A (Bruker, 2015)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      100
_diffrn_detector                 'Bruker PHOTO 100 area detector'
_diffrn_detector_area_resol_mean 7.9
_diffrn_detector_type            'CCD area detector'
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device       'three-circle diffractometer'
_diffrn_measurement_device_type  'Bruker PHOTO 100 area detector'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_monochromator  'mirror optics'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0643
_diffrn_reflns_av_unetI/netI     0.0325
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       32
_diffrn_reflns_limit_h_min       -32
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            78192
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.989
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.719
_diffrn_reflns_theta_min         2.196
_diffrn_source                   'microfocus sealed X-ray tube'
_diffrn_source_type              'Incoatec I\ms'
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.241
_exptl_absorpt_correction_T_max  0.7456
_exptl_absorpt_correction_T_min  0.6926
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'SADABS-2014/5 (Bruker,2014/5) was used for absorption correction. wR2(int) was 0.1121 before and 0.0725 after correction. The Ratio of minimum to maximum transmission is 0.8332. The \l/2 correction factor is Not present.'
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.332
_exptl_crystal_description       plate
_exptl_crystal_F_000             1440
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.41
_exptl_crystal_size_min          0.09
_refine_diff_density_max         0.312
_refine_diff_density_min         -0.283
_refine_diff_density_rms         0.057
_refine_ls_abs_structure_details
;
 Flack x determined using 3237 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.04(3)
_refine_ls_extinction_coef       0.0031(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2016/6 (Sheldrick 2016)'
_refine_ls_goodness_of_fit_ref   1.107
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     428
_refine_ls_number_reflns         7899
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.107
_refine_ls_R_factor_all          0.0433
_refine_ls_R_factor_gt           0.0408
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0210P)^2^+5.8757P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0936
_refine_ls_wR_factor_ref         0.0945
_reflns_Friedel_coverage         0.846
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.984
_reflns_number_gt                7567
_reflns_number_total             7899
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c8qo01089g2.cif
_cod_data_source_block           mo_cxy0424_0m
_cod_database_code               1554498
_shelx_shelxl_version_number     2016/6
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Ternary CH refined with riding coordinates:
 C6(H6), C7(H7), C9(H9), C13(H13), C14(H14), C26(H26), C31(H31)
2.b Secondary CH2 refined with riding coordinates:
 C10(H10A,H10B), C11(H11A,H11B), C15(H15A,H15B), C24(H24A,H24B), C25(H25A,
 H25B), C28(H28A,H28B), C30(H30A,H30B)
2.c Aromatic/amide H refined with riding coordinates:
 C2(H2), C3(H3), C18(H18), C19(H19), C21(H21), C22(H22), C33(H33), C34(H34),
 C36(H36), C37(H37)
2.d X=CH2 refined with riding coordinates:
 C38(H38A,H38B)
2.e Idealised Me refined as rotating group:
 C23(H23A,H23B,H23C), C29(H29A,H29B,H29C), C35(H35A,H35B,H35C)
;
_shelx_res_checksum              18972
_shelx_hkl_checksum              56322
_olex2_submission_special_instructions 'No special instructions were received'