A more reliable synthesis of a Gemini vitamin D analog, a potentially effective chemotherapeutic agent for the treatment of colorectal carcinomas
Santalla, Hugo; Garrido, Fátima; Gómez, Generosa; Fall, Yagamare; Organic Chemistry Frontiers 5 (2018) 2016–; doi:10.1039/C8QO00338F

data_1554315
_publ_section_title
;
 A more reliable synthesis of a Gemini vitamin D analog, a potentially
 effective chemotherapeutic agent for the treatment of colorectal
 carcinomas
;
_journal_issue                   13
_journal_name_full               'Organic Chemistry Frontiers'
_journal_page_first              2016
_journal_paper_doi               10.1039/C8QO00338F
_journal_volume                  5
_journal_year                    2018
_chemical_formula_sum            'C20 H40.5 O3.25 Si'
_chemical_formula_weight         361.11
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2018-03-27 deposited with the CCDC.
2018-05-10 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 92.798(4)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   7.3563(12)
_cell_length_b                   46.699(7)
_cell_length_c                   12.909(2)
_cell_measurement_reflns_used    9362
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      24.47
_cell_measurement_theta_min      2.62
_cell_volume                     4429.4(12)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX3'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.886
_diffrn_measured_fraction_theta_max 0.886
_diffrn_measurement_device_type  'Bruker D8 Venture Photon 100 CMOS'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0860
_diffrn_reflns_av_unetI/netI     0.1921
_diffrn_reflns_Laue_measured_fraction_full 0.886
_diffrn_reflns_Laue_measured_fraction_max 0.886
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       55
_diffrn_reflns_limit_k_min       -54
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            25433
_diffrn_reflns_point_group_measured_fraction_full 0.719
_diffrn_reflns_point_group_measured_fraction_max 0.719
_diffrn_reflns_theta_full        24.987
_diffrn_reflns_theta_max         24.987
_diffrn_reflns_theta_min         2.353
_exptl_absorpt_coefficient_mu    0.121
_exptl_absorpt_correction_T_max  0.7451
_exptl_absorpt_correction_T_min  0.6090
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS-2016/2 (Bruker AXS Inc.)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.083
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1604
_exptl_crystal_size_max          0.264
_exptl_crystal_size_mid          0.067
_exptl_crystal_size_min          0.016
_refine_diff_density_max         1.252
_refine_diff_density_min         -0.829
_refine_diff_density_rms         0.116
_refine_ls_abs_structure_details
; 
 Flack x determined using 1725 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.17(16)
_refine_ls_extinction_coef       0.0028(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.088
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     395
_refine_ls_number_reflns         11205
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.088
_refine_ls_R_factor_all          0.2634
_refine_ls_R_factor_gt           0.1846
_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^)+91.2210P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.3663
_refine_ls_wR_factor_ref         0.4018
_reflns_Friedel_coverage         0.600
_reflns_Friedel_fraction_full    0.546
_reflns_Friedel_fraction_max     0.546
_reflns_number_gt                6410
_reflns_number_total             11205
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c8qo00338f2.cif
_cod_data_source_block           32010301_0m
_cod_original_cell_volume        4429.6(12)
_cod_original_sg_symbol_H-M      'P 21'
_cod_original_formula_sum        'C20 H40.50 O3.25 Si'
_cod_database_code               1554315
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.969
_shelx_estimated_absorpt_t_max   0.998
_shelx_res_checksum              70536
_shelx_hkl_checksum              73219