An <i>ent</i>-abietane diterpenoid from <i>Doellingeria scaber</i>
Bai, Su-Ping; Zhu, Zhen-Fu; Yang, Li; Acta Crystallographica Section E 61 (2005) o2853–o2855; doi:10.1107/S1600536805025171

data_2206794
_publ_section_title
;
 An <i>ent</i>-abietane diterpenoid from <i>Doellingeria scaber</i>
;
_journal_coeditor_code           SU6216
_journal_issue                   9
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o2853
_journal_page_last               o2855
_journal_paper_doi               10.1107/S1600536805025171
_journal_volume                  61
_journal_year                    2005
_chemical_formula_iupac          'C20 H26 O4'
_chemical_formula_moiety         'C20 H26 O4'
_chemical_formula_sum            'C20 H26 O4'
_chemical_formula_weight         330.41
_chemical_name_systematic
;
4,4,8,11b-tetramethyl-2,3,4,4a,5,6,6a,7,10a,11,11a,11b-dodecahydro-
1H,9H-6a:7,10a:11-diepoxyphenanthro[3,2-b]furan-9-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
_cell_angle_alpha                90.00
_cell_angle_beta                 103.180(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   6.9120(10)
_cell_length_b                   10.7510(10)
_cell_length_c                   12.080(2)
_cell_measurement_reflns_used    27
_cell_measurement_temperature    286(2)
_cell_measurement_theta_max      14.37
_cell_measurement_theta_min      3.11
_cell_volume                     874.0(2)
_computing_cell_refinement       XSCANS
_computing_data_collection       'XSCANS (Siemens, 1994)'
_computing_data_reduction        'SHELXTL (Sheldrick, 1997b)'
_computing_molecular_graphics    'ORTEP-3 (Farrugia, 1997)'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997a)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      286(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Siemens P4'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0136
_diffrn_reflns_av_sigmaI/netI    0.0459
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            2505
_diffrn_reflns_theta_full        28.00
_diffrn_reflns_theta_max         28.00
_diffrn_reflns_theta_min         1.73
_diffrn_standards_decay_%        2.82
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.086
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.255
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             356
_exptl_crystal_size_max          0.54
_exptl_crystal_size_mid          0.46
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.159
_refine_diff_density_min         -0.121
_refine_ls_extinction_coef       0.068(5)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   0.888
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     222
_refine_ls_number_reflns         2219
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.888
_refine_ls_R_factor_all          0.0610
_refine_ls_R_factor_gt           0.0397
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0466P)^2^] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0818
_refine_ls_wR_factor_ref         0.0883
_reflns_number_gt                1496
_reflns_number_total             2219
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            su6216.cif
_cod_data_source_block           I
_cod_original_cell_volume        874.1(2)
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               2206794
_cod_database_fobs_code          2206794