A Domino Diels-Alder Approach toward the Tetracyclic Nicandrenone Framework.
Mackay, Emily G.; Nörret, Marck; Wong, Leon S.-M.; Louis, Ignace; Lawrence, Andrew L.; Willis, Anthony C.; Sherburn, Michael S.; Organic letters 17 (2015) 5517–5519; doi:10.1021/acs.orglett.5b02412

data_1540613
_publ_section_title
;
 A Domino Diels-Alder Approach toward the Tetracyclic Nicandrenone
 Framework.
;
_journal_issue                   22
_journal_name_full               'Organic letters'
_journal_page_first              5517
_journal_page_last               5519
_journal_paper_doi               10.1021/acs.orglett.5b02412
_journal_volume                  17
_journal_year                    2015
_chemical_compound_source        local
_chemical_formula_moiety         'C20 H22 O4'
_chemical_formula_sum            'C20 H22 O4'
_chemical_formula_weight         326.39
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_audit_creation_date             15-10-08
_audit_creation_method           CRYSTALS_ver_14.40
_audit_update_record
;
A  poor quality structure for identification purposes 
2007-02-21 - Report on  C20 H22 O4
             by Anthony C. Willis
             for Ignace Louis and Mick Sherburn
2007-02-21 - fails checkcif tests with warnings
2015-10-08 - revisit and tidy up
;
_cell_angle_alpha                90
_cell_angle_beta                 97.862(7)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   14.271(2)
_cell_length_b                   7.3032(10)
_cell_length_c                   15.870(2)
_cell_measurement_reflns_used    14026
_cell_measurement_temperature    200
_cell_measurement_theta_max      25
_cell_measurement_theta_min      3
_cell_volume                     1638.5(4)
_computing_cell_refinement       'Denzo/Scalepack (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius BV, 1997)'
_computing_data_reduction        'Denzo/Scalepack (Otwinowski & Minor, 1997)'
_computing_molecular_graphics
; 
ORTEP-II (Johnson 1976) in teXsan (MSC, 1992-1997)
;
_computing_publication_material  'CRYSTALS (Watkin et al 2003)'
_computing_structure_refinement  'CRYSTALS (Watkin et al 2003)'
_computing_structure_solution    'SIR97 (Altomare et al, 1999)'
_diffrn_ambient_temperature      200
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device       Area
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       ' \f and \w scans with CCD '
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.150
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            11695
_diffrn_reflns_theta_full        24
_diffrn_reflns_theta_max         24
_diffrn_reflns_theta_min         2.591
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_correction_T_min  0.86
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'DENZO/SCALEPACK (Otwinowski & Minor, 1997)'
_exptl_crystal_colour            'pale yellow'
_exptl_crystal_density_diffrn    1.323
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             696
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.060
_exptl_crystal_size_min          0.020
_refine_diff_density_max         0.65
_refine_diff_density_min         -0.52
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   0.9869
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         2573
_refine_ls_number_restraints     12
_refine_ls_R_factor_all          0.1808
_refine_ls_R_factor_gt           0.0751
_refine_ls_shift/su_max          0.0019581
_refine_ls_shift/su_mean         0.0003117
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982) 
 [weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)] 
 where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax 
 Method = Robust Weighting (Prince, 1982) 
 W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^ 
 A~i~ are: 
 24.0 34.4 17.2 3.90 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.2255
_refine_ls_wR_factor_gt          0.1758
_refine_ls_wR_factor_ref         0.2255
_reflns_limit_h_max              16
_reflns_limit_h_min              -16
_reflns_limit_k_max              8
_reflns_limit_k_min              0
_reflns_limit_l_max              18
_reflns_limit_l_min              0
_reflns_number_gt                1032
_reflns_number_total             2907
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   2.20
_oxford_diffrn_Wilson_scale      13.27
_oxford_refine_ls_r_factor_ref   0.1808
_oxford_refine_ls_scale          0.4165(14)
_oxford_reflns_number_all        2573
_oxford_reflns_threshold_expression_ref I>-10.0\s(I)
_oxford_structure_analysis_title she0703
_cod_data_source_file            ol5b02412_si_003.cif
_cod_data_source_block           compound19
_cod_original_sg_symbol_H-M      'P 1 21/c 1 '
_cod_database_code               1540613
_iucr_refine_instruction_details_constraints
;
BLOCK SCALE X'S, U'S 
RIDE C   (   3,X'S) H   (  31,X'S) 
RIDE C   (   4,X'S) H   (  41,X'S) 
RIDE C   (   6,X'S) H   (  61,X'S) 
RIDE C   (   7,X'S) H   (  71,X'S) 
RIDE C   (   8,X'S) H   (  81,X'S) 
RIDE C   (   9,X'S) H   (  91,X'S) 
RIDE C   (  10,X'S) H   ( 101,X'S) H   ( 102,X'S) 
RIDE C   (  11,X'S) H   ( 111,X'S) H   ( 112,X'S) 
RIDE C   (  12,X'S) H   ( 121,X'S) H   ( 122,X'S) 
RIDE C   (  14,X'S) H   ( 141,X'S) 
RIDE C   (  15,X'S) H   ( 151,X'S) 
RIDE C   (  16,X'S) H   ( 161,X'S) H   ( 162,X'S) 
RIDE C   (  17,X'S) H   ( 171,X'S) H   ( 172,X'S) 
RIDE C   (  20,X'S) H   ( 201,X'S) H   ( 202,X'S) H   ( 203,X'S) 
RIDE O(3,X'S) H(3,X'S) 
END                                                                             
;
_iucr_refine_instruction_details_restraints
;
U(IJ) 0.0, .02 = C(3) TO C(4), C(3) TO C(2) 
NO 
REM   HREST   START (DO NOT REMOVE THIS LINE) 
REM   HREST   END (DO NOT REMOVE THIS LINE) 
END                                                                             
;