Diastereoselectivity in the Transannular Diels‒Alder Reaction of a <i>trans</i>-<i>trans</i>-<i>trans</i> 14-Membered Macrocycle Leading to Steroids
Drouin, Marc; Couturier, Michel; Pierre Deslongchamps; Acta Crystallographica Section C 53 (1997) 1698–1701; doi:10.1107/S0108270197009578

data_2006664
_publ_section_title
;
 Diastereoselectivity in the Transannular Diels--Alder Reaction of a
 <i>trans</i>-<i>trans</i>-<i>trans</i> 14-Membered Macrocycle Leading
 to Steroids
;
_journal_issue                   11
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1698
_journal_page_last               1701
_journal_paper_doi               10.1107/S0108270197009578
_journal_volume                  53
_journal_year                    1997
_chemical_formula_moiety         'C24 H32 O7'
_chemical_formula_sum            'C24 H32 O7'
_chemical_formula_weight         432.50
_chemical_name_systematic
;
rac-3,3-bis(carbomethoxy)-18-methoxy-18-oxo-5\b,9\b,10\a-androst-6-en-17-one
;
_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'
_audit_creation_method           SHELXL
_cell_angle_alpha                90.00
_cell_angle_beta                 91.89(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.278(4)
_cell_length_b                   12.199(2)
_cell_length_c                   24.494(7)
_cell_measurement_reflns_used    24
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25
_cell_measurement_theta_min      20
_cell_volume                     2173.5(14)
_computing_cell_refinement       'NRCCAD TRUANG'
_computing_data_collection       'NRCCAD DATCOL (Le Page, White & Gabe, 1986)'
_computing_data_reduction
'NRCVAX DATRD2  (Gabe, Le Page, Charland, Lee & White, 1989)'
_computing_molecular_graphics    'ORTEP in Xtal_GX (Johnson, 1995)'
_computing_publication_material  'SHELXL93 ACTA'
_computing_structure_refinement  'SHELXL93 (Sheldrick, 1993)'
_computing_structure_solution    'NRCVAX SOLVER'
_diffrn_ambient_temperature      193
_diffrn_measurement_device       'Nonius CAD-4    '
_diffrn_measurement_method       '\q/2\q scan b/P/b '
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           'Copper K\a    '
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0175
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            4211
_diffrn_reflns_reduction_process
;
Equivalent reflections grouped and averaged (Le Page & Gabe, 1979)
;
_diffrn_reflns_theta_max         71.74
_diffrn_reflns_theta_min         1.80
_diffrn_standards_decay_%        none
_diffrn_standards_interval_time  60
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.793
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  1.000
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            rectangular
_exptl_crystal_density_diffrn    1.322
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    none
_exptl_crystal_description       colourless
_exptl_crystal_F_000             928
_exptl_crystal_size_max          .35
_exptl_crystal_size_mid          .20
_exptl_crystal_size_min          .10
_refine_diff_density_max         .323
_refine_diff_density_min         -.250
_refine_ls_abs_structure_details 'Flack (1983)'
_refine_ls_abs_structure_Flack   -0.2(3)
_refine_ls_extinction_coef       0.0014(4)
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_all   1.062
_refine_ls_goodness_of_fit_obs   1.068
_refine_ls_hydrogen_treatment    'H atoms riding'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     665
_refine_ls_number_reflns         4211
_refine_ls_number_restraints     710
_refine_ls_restrained_S_all      0.984
_refine_ls_restrained_S_obs      0.985
_refine_ls_R_factor_all          0.0626
_refine_ls_R_factor_obs          .0599
_refine_ls_shift/esd_max         -0.013
_refine_ls_shift/esd_mean        0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.1137P)^2^+1.7798P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1790
_refine_ls_wR_factor_obs         .1749
_reflns_number_observed          4010
_reflns_number_total             4211
_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            fg1287.cif
_cod_data_source_block           2
_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 

The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 3008 2015-01-20 13:52:24Z robertas 

The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc w =
1/[\s^2^(Fo^2^)+(0.1137P)^2^+1.7798P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to 'w =
1/[\s^2^(Fo^2^)+(0.1137P)^2^+1.7798P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
;
_cod_original_cell_volume        2173.6(13)
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               2006664