Diastereoselective Synthesis of Triterpenoid 1,2,4-Trioxolanes by Griesbaum Co-ozonolysis.
Kazakova, Oxana B.; Khusnutdinova, Elmira F.; Petrova, Anastasiya V.; Yamansarov, Emil Yu; Lobov, Alexander N.; Fedorova, Alexandra A.; Suponitsky, Kyrill Yu; Journal of natural products 82 (2019) 2550–2558; doi:10.1021/acs.jnatprod.9b00393

data_1552707
_publ_section_title
;
 Diastereoselective Synthesis of Triterpenoid 1,2,4-Trioxolanes by
 Griesbaum Co-ozonolysis.
;
_journal_issue                   9
_journal_name_full               'Journal of natural products'
_journal_page_first              2550
_journal_page_last               2558
_journal_paper_doi               10.1021/acs.jnatprod.9b00393
_journal_volume                  82
_journal_year                    2019
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C31 H48 O3'
_chemical_formula_sum            'C31 H48 O3'
_chemical_formula_weight         468.69
_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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/6
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.2776(5)
_cell_length_b                   13.5246(6)
_cell_length_c                   17.7209(8)
_cell_measurement_reflns_used    9319
_cell_measurement_temperature    120(2)
_cell_measurement_theta_max      28.99
_cell_measurement_theta_min      2.30
_cell_volume                     2702.9(2)
_computing_cell_refinement       'SAINT (Bruker, 2009)'
_computing_data_collection       'APEX (Bruker, 2009)'
_computing_data_reduction        'SAINT (Bruker, 2009)'
_computing_molecular_graphics    'SHELXL-2014/6 (Sheldrick, 2014)'
_computing_publication_material
'SHELXL-2014/6 (Sheldrick, 2014) and PLATON (Spek, 2009)'
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXL-2014/6 (Sheldrick, 2014)'
_diffrn_ambient_temperature      120(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.998
_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  0.0230
_diffrn_reflns_av_unetI/netI     0.0112
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            65446
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.989
_diffrn_reflns_theta_min         1.894
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    0.072
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.152
_exptl_crystal_description       prizm
_exptl_crystal_F_000             1032
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.260
_refine_diff_density_min         -0.172
_refine_diff_density_rms         0.042
_refine_ls_abs_structure_details
;
 Flack x determined using 3048 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.13(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.040
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     315
_refine_ls_number_reflns         7167
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          0.0319
_refine_ls_R_factor_gt           0.0307
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0567P)^2^+0.3484P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0826
_refine_ls_wR_factor_ref         0.0845
_reflns_Friedel_coverage         0.791
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.998
_reflns_number_gt                6954
_reflns_number_total             7167
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            np9b00393_si_001.cif
_cod_data_source_block           oxo2
_cod_database_code               1552707
_shelxl_version_number           2014/6
_shelx_res_checksum              55325
_shelx_hkl_checksum              87719