Cascading Auto-oxidative Biproline Guanylations Form Optically Active Dispacamide Dimers and Permit an Eight-Step Synthesis of (-)-Ageliferin.
Ding, Hui; Roberts, Andrew G.; Chiang, Rocky; Harran, Patrick G.; The Journal of organic chemistry 83 (2018) 7231–7238; doi:10.1021/acs.joc.8b00631

data_4035438
_publ_section_title
;
 Cascading Auto-oxidative Biproline Guanylations Form Optically Active
 Dispacamide Dimers and Permit an Eight-Step Synthesis of (-)-Ageliferin.
;
_journal_issue                   13
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              7231
_journal_page_last               7238
_journal_paper_doi               10.1021/acs.joc.8b00631
_journal_volume                  83
_journal_year                    2018
_chemical_absolute_configuration rmad
_chemical_formula_moiety         'C14 H26 Br2 N2 O4'
_chemical_formula_sum            'C14 H26 Br2 N2 O4'
_chemical_formula_weight         446.19
_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
_audit_creation_method           SHELXL-2014/6
_cell_angle_alpha                90
_cell_angle_beta                 99.505(2)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   5.0861(7)
_cell_length_b                   25.238(4)
_cell_length_c                   7.1023(13)
_cell_measurement_reflns_used    7825
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      30.46
_cell_measurement_theta_min      2.91
_cell_volume                     899.2(3)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 8.3333
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.932
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0250
_diffrn_reflns_av_unetI/netI     0.0491
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.932
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       35
_diffrn_reflns_limit_k_min       -34
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            12275
_diffrn_reflns_point_group_measured_fraction_full 0.992
_diffrn_reflns_point_group_measured_fraction_max 0.891
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         30.882
_diffrn_reflns_theta_min         1.614
_diffrn_source                   'Sealed Mo X-Ray Tube'
_exptl_absorpt_coefficient_mu    4.526
_exptl_absorpt_correction_T_max  0.75
_exptl_absorpt_correction_T_min  0.44
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2014/2 (Bruker AXS Inc.)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.648
_exptl_crystal_description       platelet
_exptl_crystal_F_000             452
_exptl_crystal_size_max          0.250
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.080
_refine_diff_density_max         0.524
_refine_diff_density_min         -0.503
_refine_diff_density_rms         0.073
_refine_ls_abs_structure_details
; 
 Flack x determined using 2141 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.032(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.918
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     201
_refine_ls_number_reflns         5079
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.918
_refine_ls_R_factor_all          0.0250
_refine_ls_R_factor_gt           0.0226
_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^)] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0449
_refine_ls_wR_factor_ref         0.0454
_reflns_Friedel_coverage         0.874
_reflns_Friedel_fraction_full    0.984
_reflns_Friedel_fraction_max     0.849
_reflns_number_gt                4811
_reflns_number_total             5079
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo8b00631_si_002.cif
_cod_data_source_block           har1603s_a
_cod_original_cell_volume        899.2(2)
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4035438
_shelx_estimated_absorpt_t_min   0.397
_shelx_estimated_absorpt_t_max   0.713
_shelxl_version_number           2014/6
_shelx_res_checksum              5221
_shelx_hkl_checksum              67998