The Supertristeroids: Large, Chiral, Molecular Bowls Prepared by Trimerization of Pentacyclic Steroidal Ketones
Qiuling Song; Douglas M. Ho; Robert A. Pascal Jr.; Journal of Organic Chemistry 72 (2007) 4449–4453; doi:10.1021/jo070458k

data_4022953
_publ_contact_author_address
;
Princeton University
Department of Chemistry
Princeton, NJ   08544-1009
USA
;
_publ_contact_author_email       rpascal@princeton.edu
_publ_contact_author_fax         '(609) 258 6746'
_publ_contact_author_name        'Professor Robert A. Pascal, Jr.'
_publ_contact_author_phone       '(609) 258 5417'
_publ_section_title
;
 The Supertristeroids: Large, Chiral, Molecular Bowls Prepared
 by Trimerization of Pentacyclic Steroidal Ketones
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              4449
_journal_page_last               4453
_journal_paper_doi               10.1021/jo070458k
_journal_volume                  72
_journal_year                    2007
_chemical_absolute_configuration rm
_chemical_compound_source        'chemical synthesis'
_chemical_formula_iupac          'C31 H52 O'
_chemical_formula_moiety         'C31 H52 O'
_chemical_formula_structural     'C31 H52 O'
_chemical_formula_sum            'C31 H52 O'
_chemical_formula_weight         440.73
_chemical_name_systematic
;
2alpha,3beta-(3'-oxocyclohexano)-5beta-cholestane
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      5
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_date             'November 28, 2006'
_audit_creation_method
;
SHELXL and manual editing of form.cif
;
_audit_update_record
;
Nov. 28, 2006  rap123f.cif        Initial CIF created by DMH.

Nov. 28, 2006  README sections    See _exptl_special_details for a brief
                                  discussion of the data collection and
                                  data reduction procedures and results.
                                  (Located just before the halfway point
                                  into this file.)

                                  See _refine_special_details for a
                                  brief discussion of the structure
                                  solution and refinement.  (Located
                                  about halfway into this file.)
                                  
                                  See _geom_special_details for a brief
                                  discussion of miscellaneous structural
                                  features.  (Located at the bottom of
                                  this file.)

Nov. 28, 2006  Sent to Checkcif.  See rap123f_checkcif.pdf for
                                  the alerts that were generated.
                                  Selected responses follow.

-------------------------------------------------------------------------

THETM01_ALERT_3_A The value of sine(theta_max)/wavelength is      < 0.550
                  Calculated sin(theta_max)/wavelength =           0.5371
PLAT027_ALERT_3_A _diffrn_reflns_theta_full (too) Low ........ 22.44 Deg.

                  The alerts THETM01_ALERT_3_A and PLAT027_ALERT_3_A are
                  not a problem.  They simply reflect the fact that the
                  crystal available for the experiment was not of
                  sufficient quality to provide usable data to higher
                  angles.  Therefore, only a 0.93 Angstrom resolution
                  data set was targeted.  Nevertheless, such a data set
                  is still considered to be of "atomic resolution", and
                  still meets the community's minimum requirements for
                  publishability in chemical journals.

PLAT024_ALERT_4_B Merging of Friedel Pairs is STRONGLY Indicated ...... !
REFLT03_ALERT_4_G MoKa measured Friedel data cannot be used to determine
                  absolute structure in a light-atom study EXCEPT under
                  VERY special conditions. It is preferred that Friedel
                  data is merged in such cases.

                  PLAT024_ALERT_4_B and REFLT03_ALERT_4_G are the same,
                  and is only a recommendation.  In truth and on theoret-
                  ical grounds, Friedel data are unique and should not
                  be merged.  Therefore, it is not wrong to ignore this
                  CheckCif recommendation, and to exercise our right to
                  retain the data as unmerged.

PLAT222_ALERT_3_A Large Non-Solvent H Ueq(max)/Ueq(min) ...... 4.10 Ratio
PLAT220_ALERT_2_B Large Non-Solvent C Ueq(max)/Ueq(min) ...... 3.41 Ratio
PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for ........ C25
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ......   5

                  PLAT222_ALERT_3_A to PLAT340_ALERT_3_C are due to the
                  presence of large thermal motions in the dimethylhexyl
                  side-chain (in particular, the terminal C26 and C27
                  methyl carbons).  Various disorder models were tried
                  but none were reasonable.  Having exhausted the
                  potential models for that particular region of electron
                  density, we were left with no recourse but to make the
                  compromise of leaving the C26 and C27 atoms as fully
                  occupied anisotropic carbons, and to accept the above
                  alerts.

STRVA01_ALERT_4_C Flack parameter is too small
                  From the CIF: _refine_ls_abs_structure_Flack     -2.210
                  From the CIF: _refine_ls_abs_structure_Flack_su   3.650
PLAT032_ALERT_4_C Std. Uncertainty in Flack Parameter too High ..... 4.00
PLAT033_ALERT_2_C Flack Parameter Value Deviates from Zero ........ -2.00

                  STRVA01_ALERT_4_C, PLAT032_ALERT_4_C and PLAT033_ALERT_
                  2_C are obviously all saying the same thing.  Yes, we
                  agree that the absolute structure cannot be determined
                  based on the intensity data.  However, the compound is
                  derived from a steroid, and hence, contains centers of
                  known chirality to begin with.  Since the chemical
                  procedures used in synthesizing the compound do not
                  involve bond making or breaking at those centers of
                  known chirality, the absolute structure of the compound
                  remains fully discernible and unequivocal based on the
                  pre-existing internal chiral labels within the molecule
                  itself.

PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C2  =  S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C3  =  R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C5  =  R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C8  =  S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C9  =  S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C10 =  S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C13 =  R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C14 =  S
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C17 =  R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of ....... C20 =  R

                  The CheckCif recommendation for the assignment of the
                  chiral centers in 2alpha,3beta-(3'-oxocyclohexano)-
                  5beta-cholestane is (2S,3R,5R,8S,9S,10S,13R,14S,17R,
                  20R).  We believe that the correct assignment is
                  (2S,3R,5R,8R,9S,10S,13R,14S,17R,20R), i.e., it may be
                  possible that CheckCIF has misassigned C8.  Regardless,
                  by visual inspection of the molecule with any molecular
                  viewer, it is obvious that the standard correct hand
                  for steroids is depicted, and any discrepancy between
                  the CheckCif assigments and our own is merely book-
                  keeping, i.e., the refined absolute structure is
                  correct as stands.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 96.248(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.5256(10)
_cell_length_b                   7.2982(4)
_cell_length_c                   33.073(3)
_cell_measurement_reflns_used    12313
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      22.44
_cell_measurement_theta_min      1.24
_cell_volume                     2765.5(4)
_computing_cell_refinement       'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1998)'
_computing_data_reduction        'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'Siemens SHELXTL (Sheldrick, 1996)'
_computing_publication_material  'Siemens SHELXTL (Sheldrick, 1996)'
_computing_structure_refinement  'Siemens SHELXTL (Sheldrick, 1996)'
_computing_structure_solution    'Siemens SHELXTL (Sheldrick, 1996)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device       'Nonius KappaCCD'
_diffrn_measurement_method       '\w scans, 1360 0.5\% rotations'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.059
_diffrn_reflns_av_sigmaI/netI    0.0588
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       -35
_diffrn_reflns_number            12313
_diffrn_reflns_theta_full        22.44
_diffrn_reflns_theta_max         22.44
_diffrn_reflns_theta_min         1.24
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.061
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.059
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Plate
_exptl_crystal_F_000             984
_exptl_crystal_size_max          0.41
_exptl_crystal_size_mid          0.23
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.117
_refine_diff_density_min         -0.147
_refine_diff_density_rms         0.030
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -2.21(365)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_all   1.125
_refine_ls_goodness_of_fit_ref   1.154
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     294
_refine_ls_number_reflns         3559
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.125
_refine_ls_restrained_S_obs      1.154
_refine_ls_R_factor_all          0.0805
_refine_ls_R_factor_gt           0.0639
_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^)+(0.0272P)^2^+2.2085P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1217
_refine_ls_wR_factor_ref         0.1142
_reflns_number_gt                3018
_reflns_number_total             3559
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            jo070458ksi20070305_110707.cif
_cod_data_source_block           rap123f
_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      'C 2'
_cod_database_code               4022953