An Asymmetric Synthesis of 1,2,4-Trioxane Anticancer Agents via Desymmetrization of Peroxyquinols through a Brønsted Acid Catalysis Cascade
David M. Rubush; Michelle A. Morges; Barbara J. Rose; Douglas H. Thamm; Tomislav Rovis; Journal of the American Chemical Society 134 (2012) 13554–13557; doi:10.1021/ja3052427

data_4118517
_publ_section_title
;
 An Asymmetric Synthesis of 1,2,4-Trioxane Anticancer Agents via
 Desymmetrization of Peroxyquinols through a Br\/onsted Acid Catalysis
 Cascade
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              13554
_journal_page_last               13557
_journal_paper_doi               10.1021/ja3052427
_journal_volume                  134
_journal_year                    2012
_chemical_absolute_configuration ad
_chemical_formula_sum            'C14 H13 Br O4'
_chemical_formula_weight         325.15
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_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-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.0393(3)
_cell_length_b                   10.7218(4)
_cell_length_c                   17.8586(7)
_cell_measurement_reflns_used    9953
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      29.62
_cell_measurement_theta_min      2.97
_cell_volume                     1347.86(9)
_computing_cell_refinement       'APEX2 (Bruker, 2009)'
_computing_data_collection       'APEX2 (Bruker, 2009)'
_computing_data_reduction        'APEX2 (Bruker, 2009)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0420
_diffrn_reflns_av_sigmaI/netI    0.0466
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            29435
_diffrn_reflns_theta_full        29.13
_diffrn_reflns_theta_max         29.13
_diffrn_reflns_theta_min         2.22
_exptl_absorpt_coefficient_mu    3.056
_exptl_absorpt_correction_T_max  0.6639
_exptl_absorpt_correction_T_min  0.4784
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'Sheldrick, G. M. (2008) SADABS. University of G\"ottingen, Germany.'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.602
_exptl_crystal_description       needle
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.698
_refine_diff_density_min         -0.443
_refine_diff_density_rms         0.081
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.009(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.096
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     174
_refine_ls_number_reflns         3638
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.096
_refine_ls_R_factor_all          0.0493
_refine_ls_R_factor_gt           0.0318
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0139P)^2^+1.0207P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0548
_refine_ls_wR_factor_ref         0.0709
_reflns_number_gt                2940
_reflns_number_total             3638
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja3052427_si_002.cif
_cod_data_source_block           rovis130_0m
_cod_database_code               4118517