Exploiting pseudo c2-symmetry for an efficient synthesis of the f-ring of the spongistatins.
Tanis, Paul S.; Infantine, Joshua R.; Leighton, James L.; Organic letters 15 (2013) 5464–5467; doi:10.1021/ol402604s

data_1512585
_publ_section_title
;
 Exploiting pseudo c2-symmetry for an efficient synthesis of the f-ring of
 the spongistatins.
;
_journal_issue                   21
_journal_name_full               'Organic letters'
_journal_page_first              5464
_journal_page_last               5467
_journal_paper_doi               10.1021/ol402604s
_journal_volume                  15
_journal_year                    2013
_chemical_absolute_configuration ad
_chemical_formula_sum            'C28 H45 N O9 Si'
_chemical_formula_weight         567.74
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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                 90.9610(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.6627(7)
_cell_length_b                   13.4490(9)
_cell_length_c                   12.0884(8)
_cell_measurement_reflns_used    9968
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      32.43
_cell_measurement_theta_min      2.27
_cell_volume                     1570.71(19)
_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-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w 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  0.0244
_diffrn_reflns_av_sigmaI/netI    0.0310
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            26117
_diffrn_reflns_theta_full        31.00
_diffrn_reflns_theta_max         31.00
_diffrn_reflns_theta_min         1.68
_exptl_absorpt_coefficient_mu    0.124
_exptl_absorpt_correction_T_max  0.9638
_exptl_absorpt_correction_T_min  0.9407
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.200
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             612
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.458
_refine_diff_density_min         -0.231
_refine_diff_density_rms         0.046
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.02(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.032
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     361
_refine_ls_number_reflns         9939
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.032
_refine_ls_R_factor_all          0.0515
_refine_ls_R_factor_gt           0.0444
_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^)+(0.0738P)^2^+0.1270P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1140
_refine_ls_wR_factor_ref         0.1201
_reflns_number_gt                8837
_reflns_number_total             9939
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol402604s_si_002.cif
_cod_data_source_block           pt4s10
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from
2011-04-26.

'_refine_ls_hydrogen_treatment' value 'CONSTR' changed
to 'constr' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      P2(1)
_cod_database_code               1512585