Protonated montmorillonite-mediated highly specific isomerization of oleanolic acid esters: application to the synthesis of Δ(13(18))-CDDO-Me.
Chen, Dongyin; Zhang, Pu; Sun, Yan; Wang, Pengfei; Zhang, Can; Kong, Lingyi; Zhang, Ji; Sun, Hongbin; Wen, Xiaoan; Organic & biomolecular chemistry 14 (2016) 11154–11161; doi:10.1039/c6ob02126c

data_7155349
_publ_section_title
;
 Protonated montmorillonite-mediated highly specific isomerization of
 oleanolic acid esters: application to the synthesis of
 \D(13(18))-CDDO-Me.
;
_journal_issue                   47
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              11154
_journal_page_last               11161
_journal_paper_doi               10.1039/c6ob02126c
_journal_volume                  14
_journal_year                    2016
_chemical_absolute_configuration unk
_chemical_formula_sum            'C32 H54 O4'
_chemical_formula_weight         502.75
_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
_audit_update_record
;
2016-09-15 deposited with the CCDC.
2016-11-02 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.104(2)
_cell_length_b                   34.297(7)
_cell_length_c                   7.1950(14)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      13
_cell_measurement_theta_min      10
_cell_volume                     2986.9(10)
_computing_cell_refinement       'CAD4 EXPRESS'
_computing_data_collection       'CAD4 EXPRESS(Enraf-Nonius,1994)'
_computing_data_reduction        'XCAD4(Harms & Wocadlo,1995)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Nonius cad4'
_diffrn_measurement_method       \w/2\q
_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  0.0579
_diffrn_reflns_av_sigmaI/netI    0.0662
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       41
_diffrn_reflns_limit_k_min       -41
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            6152
_diffrn_reflns_theta_full        25.31
_diffrn_reflns_theta_max         25.31
_diffrn_reflns_theta_min         1.19
_diffrn_standards_decay_%        1
_diffrn_standards_interval_count 200
_diffrn_standards_interval_time  2h
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.071
_exptl_absorpt_correction_T_max  0.9859
_exptl_absorpt_correction_T_min  0.9790
_exptl_absorpt_correction_type   psi-scan
_exptl_crystal_density_diffrn    1.118
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1112
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.213
_refine_diff_density_min         -0.178
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.006
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     327
_refine_ls_number_reflns         5433
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.1422
_refine_ls_R_factor_gt           0.0789
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0700P)^2^+2.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1635
_refine_ls_wR_factor_ref         0.1978
_reflns_number_gt                3094
_reflns_number_total             5433
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c6ob02126c2.cif
_cod_data_source_block           x
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 4268 2015-11-12 08:31:59Z antanas 

 Adding full bibliography for 7155349.cif.
;
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               7155349