The pseudoguaianolide peruvin
Fronczek, Frank R.; Acta Crystallographica Section E 58 (2002) o871–o873; doi:10.1107/S1600536802011832

data_2201605
_publ_section_title
;
 The pseudoguaianolide peruvin
;
_journal_issue                   8
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o871
_journal_page_last               o873
_journal_paper_doi               10.1107/S1600536802011832
_journal_volume                  58
_journal_year                    2002
_chemical_formula_iupac          'C15 H20 O4'
_chemical_formula_moiety         'C15 H20 O4'
_chemical_formula_sum            'C15 H20 O4'
_chemical_formula_weight         264.31
_chemical_name_common            peruvin
_chemical_name_systematic
;
(3aR,4aS,7aR,8S,9aR)-decahydro-7a-hydroxy-4a,8-dimethyl-
methylene-azuleno[6,5-b]furan-2,5-dione
;
_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
_cell_angle_beta                 103.247(8)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   7.0647(8)
_cell_length_b                   12.0073(13)
_cell_length_c                   8.1788(11)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    120
_cell_measurement_theta_max      43.5
_cell_measurement_theta_min      21.1
_cell_volume                     675.33(14)
_computing_cell_refinement       'CAD-4 EXPRESS'
_computing_data_collection       'CAD-4 EXPRESS (Enraf-Nonius, 1994)'
_computing_data_reduction        'XCAD4 (Harms & Wocadlo, 1995)'
_computing_molecular_graphics    'ORTEP-3 for Windows (Farrugia, 1997)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Altomare et al., 1997)'
_diffrn_ambient_temperature      120
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.00
_diffrn_measurement_device       'Enraf-Nonius CAD-4'
_diffrn_measurement_device_type  \k-geometry
_diffrn_measurement_method       \w/2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54180
_diffrn_reflns_av_R_equivalents  0.037
_diffrn_reflns_av_sigmaI/netI    0.011
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            2686
_diffrn_reflns_theta_full        74.9
_diffrn_reflns_theta_max         74.9
_diffrn_reflns_theta_min         5.5
_diffrn_standards_decay_%        2.0
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.763
_exptl_absorpt_correction_T_max  0.791
_exptl_absorpt_correction_T_min  0.757
_exptl_absorpt_correction_type   '\y scan'
_exptl_absorpt_process_details   '(North et al., 1968)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.300
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             284
_exptl_crystal_size_max          0.47
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.29
_refine_diff_density_min         -0.21
_refine_ls_abs_structure_details 'Flack (1983); 944 Friedel pairs'
_refine_ls_abs_structure_Flack   0.1(2)
_refine_ls_extinction_coef       0.033(3)
_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   1.097
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     176
_refine_ls_number_reflns         2400
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.097
_refine_ls_R_factor_all          0.037
_refine_ls_R_factor_gt           0.037
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w = 1/[\s^2^(Fo^2^)+(0.0696P)^2^+0.3022P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.109
_refine_ls_wR_factor_ref         0.109
_reflns_number_gt                2395
_reflns_number_total             2400
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            om6096.cif
_cod_data_source_block           I
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               2201605
_cod_database_fobs_code          2201605