Asymmetric Synthesis of gem-Difluoromethylenated Linear Triquinanes via Cascade gem-Difluoroalkyl Radical Cyclization.
Thaharn, Watcharaporn; Soorukram, Darunee; Kuhakarn, Chutima; Tuchinda, Patoomratana; Pakawatchai, Chaveng; Saithong, Saowanit; Reutrakul, Vichai; Pohmakotr, Manat; The Journal of organic chemistry 80 (2015) 816–827; doi:10.1021/jo5022579

data_4030547
_publ_section_title
;
 Asymmetric Synthesis of gem-Difluoromethylenated Linear Triquinanes via
 Cascade gem-Difluoroalkyl Radical Cyclization.
;
_journal_issue                   2
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              816
_journal_page_last               827
_journal_paper_doi               10.1021/jo5022579
_journal_volume                  80
_journal_year                    2015
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C19 H22 F2 O2'
_chemical_formula_sum            'C19 H22 F2 O2'
_chemical_formula_weight         320.36
_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
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.0115(4)
_cell_length_b                   7.0059(4)
_cell_length_c                   38.087(2)
_cell_measurement_reflns_used    1704
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      19.59
_cell_measurement_theta_min      3.10
_cell_volume                     1604.07(16)
_computing_cell_refinement       'SAINT (Bruker, 2003)'
_computing_data_collection       'SMART (Bruker, 1998)'
_computing_data_reduction        'SAINT (Bruker, 2003)'
_computing_molecular_graphics    'Mercury 3.3 (Macrea <i>et al</i>., 2008)'
_computing_publication_material  'WinGX publication routines (Farrugia, 2012)'
_computing_structure_refinement  'SHELXL-2014 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.950
_diffrn_measured_fraction_theta_max 0.982
_diffrn_measurement_device_type  'Bruker APEX CCD area-detector'
_diffrn_measurement_method       'Frames, each covering 0.3 \% in \w'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1061
_diffrn_reflns_av_unetI/netI     0.0752
_diffrn_reflns_Laue_measured_fraction_full 0.950
_diffrn_reflns_Laue_measured_fraction_max 0.982
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       45
_diffrn_reflns_limit_l_min       -45
_diffrn_reflns_number            14779
_diffrn_reflns_point_group_measured_fraction_full 0.951
_diffrn_reflns_point_group_measured_fraction_max 0.984
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         24.994
_diffrn_reflns_theta_min         2.956
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.100
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.711474
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Bruker, 2003)'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.327
_exptl_crystal_density_method    none
_exptl_crystal_description       Block
_exptl_crystal_F_000             680
_exptl_crystal_size_max          0.286
_exptl_crystal_size_mid          0.106
_exptl_crystal_size_min          0.053
_refine_diff_density_max         0.217
_refine_diff_density_min         -0.184
_refine_diff_density_rms         0.048
_refine_ls_abs_structure_details
;
 Flack x determined using 796 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.3(8)
_refine_ls_extinction_coef       2.59(14)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.169
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     211
_refine_ls_number_reflns         2758
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.169
_refine_ls_R_factor_all          0.0777
_refine_ls_R_factor_gt           0.0655
_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^)+(0.0694P)^2^+0.0693P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1391
_refine_ls_wR_factor_ref         0.1450
_reflns_Friedel_coverage         0.667
_reflns_Friedel_fraction_full    0.953
_reflns_Friedel_fraction_max     0.988
_reflns_number_gt                2378
_reflns_number_total             2758
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo5022579_si_001.cif
_cod_data_source_block           shelx
_cod_original_cell_volume        1604.05(17)
_cod_database_code               4030547
_shelxl_version_number           2014-3
_shelx_res_checksum              95633
_shelx_hkl_checksum              18557