Benzyne-Mediated Nonconcerted Pathway toward Synthesis of Sterically Crowded [5]- and [7]Oxahelicenoids, Stereochemical and Theoretical Studies, and Optical Resolution of Helicenoids.
Gawade, Prashant M.; Khose, Vaibhav N.; Badani, Purav M.; Hasan, Mohammed; Kaabel, Sandra; Mobin, Shaikh M.; Borovkov, Victor; Karnik, Anil V.; The Journal of organic chemistry 84 (2019) 860–868; doi:10.1021/acs.joc.8b02507

data_4036001
_publ_section_title
;
 Benzyne-Mediated Nonconcerted Pathway toward Synthesis of Sterically
 Crowded [5]- and [7]Oxahelicenoids, Stereochemical and Theoretical
 Studies, and Optical Resolution of Helicenoids.
;
_journal_issue                   2
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              860
_journal_page_last               868
_journal_paper_doi               10.1021/acs.joc.8b02507
_journal_volume                  84
_journal_year                    2019
_chemical_formula_sum            'C32 H20 Br2 O2'
_chemical_formula_weight         596.30
_space_group_IT_number           41
_space_group_name_Hall           'A 2 -2ab'
_space_group_name_H-M_alt        'A e a 2'
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_H-M   'A e a 2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.2662(2)
_cell_length_b                   15.6756(2)
_cell_length_c                   14.1746(3)
_cell_measurement_reflns_used    5393
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      70.9910
_cell_measurement_theta_min      3.9470
_cell_volume                     2503.30(8)
_computing_cell_refinement       'CrysAlis RED, Oxford Diffraction Ltd.,'
_computing_data_collection       'CrysAlis CCD, Oxford Diffraction Ltd.,'
_computing_data_reduction        'CrysAlis RED, Oxford Diffraction Ltd.,'
_computing_molecular_graphics    Ortep3
_computing_publication_material  Shelx97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 15.9948
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'OXFORD DIFFRACTION SUPER NOVA'
_diffrn_measurement_method       \w/q-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Micro-Focus (Cu) X-ray Source'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.5418
_diffrn_reflns_av_R_equivalents  0.0255
_diffrn_reflns_av_unetI/netI     0.0166
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            7638
_diffrn_reflns_theta_full        71.32
_diffrn_reflns_theta_max         71.32
_diffrn_reflns_theta_min         5.64
_exptl_absorpt_coefficient_mu    4.330
_exptl_absorpt_correction_T_max  0.5824
_exptl_absorpt_correction_T_min  0.4358
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlis RED, Oxford Diffraction Ltd.,
Version 1.171.31.7 (release 18-10-2006 CrysAlis171 .NET)
(compiled Oct 18 2006,16:28:17)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.582
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1192
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.711
_refine_diff_density_min         -0.918
_refine_diff_density_rms         0.085
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.01(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.082
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           full
_refine_ls_number_parameters     163
_refine_ls_number_reflns         2043
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.082
_refine_ls_R_factor_all          0.0467
_refine_ls_R_factor_gt           0.0460
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0954P)^2^+1.5163P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1336
_refine_ls_wR_factor_ref         0.1351
_reflns_number_gt                1988
_reflns_number_total             2043
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo8b02507_si_004.cif
_cod_data_source_block           shelx
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_symmetry_cell_setting' value 'Orthorhombic' was changed
to 'orthorhombic' in accordance with the
/home/data/users/saulius/crontab/automatic-downloads/current/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

Automatic conversion script
Id: cif_fix_values 6909 2019-04-08 15:41:33Z antanas 

2022-01-02
Z value and formula fixed to values more according to usual
chemical conventions.                 miguel
;
_cod_original_formula_sum            'C42.67 H26.67 Br2.67 O2.67'
_cod_original_formula_weight         795.07
_cod_original_formula_units_Z            3
_cod_original_sg_symbol_H-M      'A b a 2'
_cod_database_code               4036001