Crystallographic Evidence of [1,5]Prototropic Shifts Occurring upon Transannular Diels‒Alder Reaction of a 14-Membered Macrocycle leading to a 5α-Steroid Skeleton
Drouin, Marc; Couturier, Michel; Deslongchamps, Pierre; Acta Crystallographica Section C 54 (1998) 256–261; doi:10.1107/S0108270197013310

data_2007006
_publ_section_title
;
 Crystallographic Evidence of [1,5]Prototropic Shifts Occurring upon
 Transannular Diels--Alder Reaction of a 14-Membered Macrocycle leading
 to a 5\a-Steroid Skeleton
;
_journal_issue                   2
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              256
_journal_page_last               261
_journal_paper_doi               10.1107/S0108270197013310
_journal_volume                  54
_journal_year                    1998
_chemical_formula_structural     'C24 H30 O8'
_chemical_formula_sum            'C24 H30 O8'
_chemical_formula_weight         446.48
_chemical_name_systematic
;
rac-(5Z,11Z,13Z)-1,8,8-Tris(methoxycarbonyl)-5-methyl-3,17-
dioxobicyclo[12.3.0]heptadeca-5,11,13-triene
;
_space_group_IT_number           2
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_symmetry_space_group_name_Hall  '-P 1'
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_audit_creation_method           SHELXL
_cell_angle_alpha                108.201(10)
_cell_angle_beta                 101.221(9)
_cell_angle_gamma                98.791(9)
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_cell_length_b                   10.5526(13)
_cell_length_c                   13.657(2)
_cell_measurement_reflns_used    24
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      40
_cell_measurement_theta_min      30
_cell_volume                     1199.7(3)
_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'
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_computing_structure_solution    'NRCVAX SOLVER'
_diffrn_ambient_temperature      293.0(10)
_diffrn_measurement_device       'Nonius CAD-4'
_diffrn_measurement_method       '\w/2\q scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0000
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_diffrn_reflns_limit_h_max       10
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_diffrn_reflns_limit_k_min       0
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_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            4658
_diffrn_reflns_reduction_process
;
Equivalent reflections grouped and averaged (Le Page & Gabe, 1979)
;
_diffrn_reflns_theta_max         72.02
_diffrn_reflns_theta_min         3.53
_diffrn_standards_decay_%        <1
_diffrn_standards_interval_count 100
_diffrn_standards_number         2
_exptl_absorpt_coefficient_mu    0.768
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
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_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    none
_exptl_crystal_description       rectangular
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_refine_diff_density_max         .181
_refine_diff_density_min         -.120
_refine_ls_extinction_coef       0.0077(9)
_refine_ls_extinction_method     SHELXL
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_refine_ls_hydrogen_treatment    constr
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_refine_ls_restrained_S_obs      0.959
_refine_ls_R_factor_all          0.0555
_refine_ls_R_factor_obs          .0462
_refine_ls_shift/esd_max         0.000
_refine_ls_shift/esd_mean        0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0923P)^2^+0.1199P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1551
_refine_ls_wR_factor_obs         .1453
_reflns_number_observed          3625
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_reflns_observed_criterion       >2sigma(I)
_cod_data_source_file            fg1350.cif
_cod_data_source_block           2
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
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:

'_symmetry_cell_setting' value 'Triclinic' changed to 'triclinic'
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_values 1715 2011-07-08 13:25:40Z adriana 

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^)+(0.0923P)^2^+0.1199P] 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^)+(0.0923P)^2^+0.1199P] 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        1199.7(2)
_cod_database_code               2007006