Total Synthesis of (-)-Batrachotoxinin A: A Local-Desymmetrization Approach.
Guo, Yinliang; Guo, Zhixian; Lu, Jia-Tian; Fang, Runting; Chen, Si-Cong; Luo, Tuoping; Journal of the American Chemical Society 142 (2020) 3675–3679; doi:10.1021/jacs.9b12882

data_4134193
_publ_section_title
;
 Total Synthesis of (-)-Batrachotoxinin A: A Local-Desymmetrization
 Approach.
;
_journal_issue                   8
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              3675
_journal_page_last               3679
_journal_paper_doi               10.1021/jacs.9b12882
_journal_volume                  142
_journal_year                    2020
_chemical_absolute_configuration ad
_chemical_formula_sum            'C14 H18 Br2 O3'
_chemical_formula_weight         394.10
_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   geom
_atom_sites_solution_primary     dual
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 105.261(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   12.7153(3)
_cell_length_b                   8.0160(2)
_cell_length_c                   14.8477(4)
_cell_measurement_reflns_used    13553
_cell_measurement_temperature    180.00(10)
_cell_measurement_theta_max      27.9090
_cell_measurement_theta_min      2.4240
_cell_volume                     1460.00(7)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      180.00(10)
_diffrn_detector                 'CCD plate'
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy R, DW system, HyPix'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0469
_diffrn_reflns_av_unetI/netI     0.0379
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            30303
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.484
_diffrn_reflns_theta_min         2.454
_diffrn_source                   'fine-focus sealed X-ray tube'
_diffrn_source_type              'Enhance (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    5.553
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.67303
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.39.29a (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.793
_exptl_crystal_description       block
_exptl_crystal_F_000             784
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.11
_refine_diff_density_max         0.743
_refine_diff_density_min         -0.407
_refine_diff_density_rms         0.083
_refine_ls_abs_structure_details
;
 Flack x determined using 2523 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.003(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.015
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     347
_refine_ls_number_reflns         6709
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.014
_refine_ls_R_factor_all          0.0420
_refine_ls_R_factor_gt           0.0362
_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^)+(0.0473P)^2^+0.3011P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0774
_refine_ls_wR_factor_ref         0.0793
_reflns_Friedel_coverage         0.866
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     1.000
_reflns_number_gt                6152
_reflns_number_total             6709
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja9b12882_si_004.cif
_cod_data_source_block           3
_cod_depositor_comments
'Adding full bibliography for 4134185--4134193.cif.'
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4134193
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              4415
_shelx_hkl_checksum              10779