Water Enables an Asymmetric Cross Reaction of α-Keto Acid to α-Keto Ester for the Synthesis of Quaternary Isotetronic Acid
Li, Can; Liu, Yan; Wang, Kai; Ping, Chen; Zhang, Boyu; Guo, Wengang; Chemical Communications  (2019) –; doi:10.1039/C9CC06356K

data_7124287
_publ_section_title
;
 Water Enables an Asymmetric Cross Reaction of \a-Keto Acid to \a-Keto
 Ester for the Synthesis of Quaternary Isotetronic Acid
;
_journal_name_full               'Chemical Communications'
_journal_paper_doi               10.1039/C9CC06356K
_journal_year                    2019
_chemical_absolute_configuration ad
_chemical_formula_sum            'C18 H21 Br O5'
_chemical_formula_weight         397.26
_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
_audit_creation_method           SHELXL-2013
_audit_update_record
;
2018-01-11 deposited with the CCDC.    2019-09-30 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.3224(5)
_cell_length_b                   11.8122(10)
_cell_length_c                   24.672(2)
_cell_measurement_reflns_used    4442
_cell_measurement_temperature    133(2)
_cell_measurement_theta_max      50.778
_cell_measurement_theta_min      4.774
_cell_volume                     1842.5(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-2013 (Sheldrick, 2013)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      133(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_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  0.0272
_diffrn_reflns_av_unetI/netI     0.0443
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            13332
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.997
_diffrn_reflns_theta_min         1.911
_exptl_absorpt_coefficient_mu    2.254
_exptl_absorpt_correction_T_max  0.7461
_exptl_absorpt_correction_T_min  0.5948
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.432
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             816
_exptl_crystal_size_max          0.211
_exptl_crystal_size_mid          0.166
_exptl_crystal_size_min          0.123
_refine_diff_density_max         0.458
_refine_diff_density_min         -0.504
_refine_diff_density_rms         0.054
_refine_ls_abs_structure_details
; 
 Flack x determined using 1271 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons and Flack (2004), Acta Cryst. A60, s61). 
;
_refine_ls_abs_structure_Flack   0.010(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.051
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     312
_refine_ls_number_reflns         3623
_refine_ls_number_restraints     36
_refine_ls_restrained_S_all      1.051
_refine_ls_R_factor_all          0.0389
_refine_ls_R_factor_gt           0.0327
_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^)+(0.0274P)^2^+1.0500P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0783
_refine_ls_wR_factor_ref         0.0812
_reflns_Friedel_coverage         0.716
_reflns_Friedel_fraction_full    0.998
_reflns_Friedel_fraction_max     0.998
_reflns_number_gt                3276
_reflns_number_total             3623
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c9cc06356k2.cif
_cod_data_source_block           mo_dm15220_0m
_cod_database_code               7124287
_shelxl_version_number           2013-4
_shelx_res_checksum              46587