A Stereoselective Approach to the Azaspiro[5.5]undecane Ring System Using a Conjugate Addition/Dipolar Cycloaddition Cascade: Application to the Total Synthesis of (±)-2,7,8-epi-Perhydrohistrionicotoxin
Michael S. Wilson; Albert Padwa; Journal of Organic Chemistry 73 (2008) 9601–9609; doi:10.1021/jo801295e

data_4023917
_publ_section_title
;
 A Stereoselective Approach to the Azaspiro[5.5]undecane Ring System
 Using a Conjugate Addition/Dipolar Cycloaddition Cascade: Application
 to the Total Synthesis of (+-)-2,7,8-epi-Perhydrohistrionicotoxin
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              9601
_journal_page_last               9609
_journal_paper_doi               10.1021/jo801295e
_journal_volume                  73
_journal_year                    2008
_chemical_formula_sum            'C32 H47 N O6 S2 Si'
_chemical_formula_weight         633.92
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 109.276(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.9551(9)
_cell_length_b                   18.5416(14)
_cell_length_c                   15.8097(12)
_cell_measurement_reflns_used    9651
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      66.89
_cell_measurement_theta_min      2.96
_cell_volume                     3308.0(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.943
_diffrn_measured_fraction_theta_max 0.943
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0356
_diffrn_reflns_av_sigmaI/netI    0.0384
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            15780
_diffrn_reflns_theta_full        66.88
_diffrn_reflns_theta_max         66.88
_diffrn_reflns_theta_min         3.80
_exptl_absorpt_coefficient_mu    2.154
_exptl_absorpt_correction_T_max  1.00
_exptl_absorpt_correction_T_min  0.681082
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.273
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1360
_exptl_crystal_size_max          0.42
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.16
_refine_diff_density_max         0.310
_refine_diff_density_min         -0.275
_refine_diff_density_rms         0.052
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.198
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     385
_refine_ls_number_reflns         5547
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.198
_refine_ls_R_factor_all          0.0498
_refine_ls_R_factor_gt           0.0405
_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^)+(0.0600P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1070
_refine_ls_wR_factor_ref         0.1111
_reflns_number_gt                4694
_reflns_number_total             5547
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo801295e_si_002.cif
_cod_data_source_block           Diasteromer_17a
_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 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4023917