Epimerization of Tertiary Carbon Centers via Reversible Radical Cleavage of Unactivated C(sp<sup>3</sup>)-H Bonds.
Wang, Yaxin; Hu, Xiafei; Morales-Rivera, Cristian A; Li, Guo-Xing; Huang, Xin; He, Gang; Liu, Peng; Chen, Gong; Journal of the American Chemical Society 140 (2018) 9678–9684; doi:10.1021/jacs.8b05753

data_4132711
_publ_section_title
;
 Epimerization of Tertiary Carbon Centers via Reversible Radical Cleavage
 of Unactivated C(sp<sup>3</sup>)-H Bonds.
;
_journal_issue                   30
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              9678
_journal_page_last               9684
_journal_paper_doi               10.1021/jacs.8b05753
_journal_volume                  140
_journal_year                    2018
_chemical_absolute_configuration R
_chemical_formula_moiety         'C28 H38 O4'
_chemical_formula_sum            'C28 H38 O4'
_chemical_formula_weight         438.58
_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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             2018-04-11
_audit_creation_method
;
Olex2 1.2-beta
(compiled 2018.04.03 svn.r3497 for OlexSys, GUI svn.r5486)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.7029(4)
_cell_length_b                   14.6019(6)
_cell_length_c                   21.1006(9)
_cell_measurement_reflns_used    3264
_cell_measurement_temperature    120(10)
_cell_measurement_theta_max      27.7640
_cell_measurement_theta_min      3.8610
_cell_volume                     2373.33(19)
_computing_cell_refinement       'CrysAlisPro 1.171.38.43f (Rigaku OD, 2015)'
_computing_data_collection       'CrysAlisPro 1.171.38.43f (Rigaku OD, 2015)'
_computing_data_reduction        'CrysAlisPro 1.171.38.43f (Rigaku OD, 2015)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL (Sheldrick, 2008)'
_computing_structure_solution    'XS (Sheldrick, 2008)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      120(10)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 16.2116
_diffrn_detector_type            Eos
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
--------------------------------------------------------------------------
  1  \w     63.00  91.00   1.00   12.50    --   18.94 178.00 -90.00   28
  2  \w    -30.00  50.00   1.00   12.50    --  -19.25  57.00 -90.00   80
  3  \w    -92.00  39.00   1.00   12.50    --  -19.25   0.00  90.00  131
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'SuperNova, Single source at offset, Eos'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0210792000
_diffrn_orient_matrix_UB_12      0.0363735000
_diffrn_orient_matrix_UB_13      -0.0208915000
_diffrn_orient_matrix_UB_21      -0.0863966000
_diffrn_orient_matrix_UB_22      0.0164195000
_diffrn_orient_matrix_UB_23      0.0020661000
_diffrn_orient_matrix_UB_31      0.0236437000
_diffrn_orient_matrix_UB_32      0.0277026000
_diffrn_orient_matrix_UB_33      0.0262783000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0347
_diffrn_reflns_av_unetI/netI     0.0501
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            9720
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.996
_diffrn_reflns_theta_full        25.005
_diffrn_reflns_theta_max         25.005
_diffrn_reflns_theta_min         2.952
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'SuperNova (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.69479
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.38.43f (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear light colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.227
_exptl_crystal_description       block
_exptl_crystal_F_000             952
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.147
_refine_diff_density_min         -0.203
_refine_diff_density_rms         0.036
_refine_ls_abs_structure_details
;
 Flack x determined using 1323 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.8(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     292
_refine_ls_number_reflns         4167
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.0500
_refine_ls_R_factor_gt           0.0398
_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^)+(0.0380P)^2^+0.0890P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0825
_refine_ls_wR_factor_ref         0.0896
_reflns_Friedel_coverage         0.738
_reflns_Friedel_fraction_full    0.995
_reflns_Friedel_fraction_max     0.994
_reflns_number_gt                3604
_reflns_number_total             4167
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja8b05753_si_003.cif
_cod_data_source_block           p170606a
_cod_original_cell_volume        2373.34(19)
_cod_database_code               4132711
_shelx_shelxl_version_number     2014/7
_chemical_oxdiff_formula         'C H O N'
_chemical_oxdiff_usercomment     hg-wyx
_reflns_odcompleteness_completeness 99.64
_reflns_odcompleteness_iscentric 1
_reflns_odcompleteness_theta     26.32
_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:
 C17(H17), C3(H3), C7(H7), C11(H11), C12(H12), C19(H19)
2.b Secondary CH2 refined with riding coordinates:
 C15(H15A,H15B), C14(H14A,H14B), C8(H8A,H8B), C4(H4A,H4B), C9(H9A,H9B), C5(H5A,
 H5B), C10(H10A,H10B), C20(H20A,H20B), C21(H21A,H21B)
2.c Aromatic/amide H refined with riding coordinates:
 C24(H24), C28(H28), C25(H25), C27(H27), C26(H26)
2.d Idealised Me refined as rotating group:
 C18(H18A,H18B,H18C), C13(H13A,H13B,H13C), C1(H1A,H1B,H1C)
;
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.744
_oxdiff_exptl_absorpt_empirical_full_min 0.518