Asymmetric Cyclopropanation of β,γ-Unsaturated α-Ketoesters with Stabilized Sulfur Ylides Catalyzed by C2-Symmetric Ureas
Ying Cheng; Jing An; Liang-Qiu Lu; Lan Luo; Zheng-Yi Wang; Jia-Rong Chen; Wen-Jing Xiao; Journal of Organic Chemistry 76 (2011) 281–284; doi:10.1021/jo101699r

data_4025944
_publ_section_title
;
 Asymmetric Cyclopropanation of \b,\g-Unsaturated \a-Ketoesters with
 Stabilized Sulfur Ylides Catalyzed by C2-Symmetric Ureas
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              281
_journal_page_last               284
_journal_paper_doi               10.1021/jo101699r
_journal_volume                  76
_journal_year                    2011
_chemical_formula_sum            'C19 H15 Br O4'
_chemical_formula_weight         387.22
_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                   5.6153(8)
_cell_length_b                   16.599(2)
_cell_length_c                   18.194(2)
_cell_measurement_reflns_used    3132
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      22.08
_cell_measurement_theta_min      2.55
_cell_volume                     1695.8(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_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  0.0303
_diffrn_reflns_av_sigmaI/netI    0.0562
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            11450
_diffrn_reflns_theta_full        28.32
_diffrn_reflns_theta_max         28.32
_diffrn_reflns_theta_min         2.24
_exptl_absorpt_coefficient_mu    2.443
_exptl_absorpt_correction_T_max  0.7922
_exptl_absorpt_correction_T_min  0.6959
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.517
_exptl_crystal_description       block
_exptl_crystal_F_000             784
_exptl_crystal_size_max          0.16
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.526
_refine_diff_density_min         -0.253
_refine_diff_density_rms         0.048
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.024(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     218
_refine_ls_number_reflns         4163
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.010
_refine_ls_R_factor_all          0.0707
_refine_ls_R_factor_gt           0.0440
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0478P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0993
_refine_ls_wR_factor_ref         0.1087
_reflns_number_gt                2848
_reflns_number_total             4163
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo101699r_si_001.cif
_cod_data_source_block           t
_cod_database_code               4025944