Absolute structures and conformations of the spongian diterpenes spongia-13(16),14-dien-3-one, epispongiadiol and spongiadiol
Yong, Ken W. L.; Garson, Mary J.; Bernhardt, Paul V.; Acta Crystallographica Section C 65 (2009) o167–o170; doi:10.1107/S0108270109008816

data_2017071
_publ_section_title
;
 Absolute structures and conformations of the spongian diterpenes
 spongia-13(16),14-dien-3-one, epispongiadiol and spongiadiol
;
_journal_coeditor_code           SQ3189
_journal_issue                   4
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              o167
_journal_page_last               o170
_journal_paper_doi               10.1107/S0108270109008816
_journal_volume                  65
_journal_year                    2009
_chemical_formula_iupac          'C20 H28 O2'
_chemical_formula_moiety         'C20 H28 O2'
_chemical_formula_sum            'C20 H28 O2'
_chemical_formula_weight         300.42
_chemical_name_systematic
;
(3bR,5aR,9aR,9bR)-3b,6,6,9a-tetramethyl-4,5,5a,6,8,9,9a,9b,10,11-
decahydrophenanthro[1,2-<i>c</i>]furan-7(3bH)-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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.3
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 101.9300(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   12.33360(10)
_cell_length_b                   7.41240(10)
_cell_length_c                   18.24760(10)
_cell_measurement_reflns_used    14597
_cell_measurement_temperature    130(2)
_cell_measurement_theta_max      62.3306
_cell_measurement_theta_min      3.6602
_cell_volume                     1632.19(3)
_computing_cell_refinement       'CrysAlis RED (Oxford Diffraction, 2008)'
_computing_data_collection       'CrysAlis CCD (Oxford Diffraction, 2008)'
_computing_data_reduction        'CrysAlis RED (Oxford Diffraction, 2008)'
_computing_molecular_graphics
;
ORTEP-3 for Windows (Farrugia, 1997) and PLUTON (Spek, 1991)
;
_computing_publication_material  'WinGX (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS86 (Sheldrick, 2008)'
_diffrn_ambient_temperature      130(2)
_diffrn_detector_area_resol_mean 16.0696
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Oxford Diffraction Gemini S Ultra'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_source         'Ultra (Cu) X-ray source'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.5418
_diffrn_reflns_av_R_equivalents  0.0335
_diffrn_reflns_av_sigmaI/netI    0.0650
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            26930
_diffrn_reflns_theta_full        62.46
_diffrn_reflns_theta_max         62.3306
_diffrn_reflns_theta_min         3.6602
_exptl_absorpt_coefficient_mu    0.594
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.223
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.173
_refine_diff_density_min         -0.137
_refine_ls_abs_structure_details 'Flack (1983), with how many Friedel pairs?'
_refine_ls_abs_structure_Flack   -0.06(14)
_refine_ls_extinction_coef       0.0035(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL97 (Sheldrick, 2008)'
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     406
_refine_ls_number_reflns         5168
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.0304
_refine_ls_R_factor_gt           0.0274
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0460P)^2^+0.0646P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0692
_refine_ls_wR_factor_ref         0.0704
_reflns_number_gt                4826
_reflns_number_total             5168
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sq3189.cif
_cod_data_source_block           I
_cod_database_code               2017071
_cod_database_fobs_code          2017071