1-(5-Hydroxy-2,2,8,8-tetramethyl-2<i>H</i>,8<i>H</i>-pyrano[2,3-<i>f</i>]chromen-6-yl)ethanone
Pawar, Sunayna; Cheddie, Adele; Omondi, Bernard; Koorbanally, Neil Anthony; Acta Crystallographica Section E 68 (2012) o3048–; doi:10.1107/S160053681204055X

data_2236321
_publ_section_title
;
 1-(5-Hydroxy-2,2,8,8-tetramethyl-2<i>H</i>,8<i>H</i>-pyrano[2,3-<i>f</i>]chromen-6-yl)ethanone
;
_journal_coeditor_code           HG5251
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section E'
_journal_page_first              o3048
_journal_paper_doi               10.1107/S160053681204055X
_journal_volume                  68
_journal_year                    2012
_chemical_formula_iupac          'C18 H20 O4'
_chemical_formula_moiety         'C18 H20 O4'
_chemical_formula_sum            'C18 H20 O4'
_chemical_formula_weight         300.34
_chemical_name_systematic
;
1-(5-Hydroxy-2,2,8,8-tetramethyl-2<i>H</i>,8<i>H</i>-pyrano[2,3-<i>f</i>]
chromen-6-yl)ethanone
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -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      2.4
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                102.180(3)
_cell_angle_beta                 102.621(3)
_cell_angle_gamma                110.671(3)
_cell_formula_units_Z            2
_cell_length_a                   8.5039(6)
_cell_length_b                   9.5370(6)
_cell_length_c                   10.7859(7)
_cell_measurement_reflns_used    17650
_cell_measurement_temperature    446(2)
_cell_measurement_theta_max      28.48
_cell_measurement_theta_min      2.04
_cell_volume                     757.86(9)
_computing_cell_refinement       'SAINT-plus (Bruker, 2008)'
_computing_data_collection       'APEX2 (Bruker, 2008)'
_computing_data_reduction        'SAINT-Plus and XPREP (Bruker, 2008)'
_computing_molecular_graphics    'ORTEP3 (Farrugia, 2012)'
_computing_publication_material  'WinGX (Farrugia, 2012)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      446(2)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_diffrn_measurement_device_type  'Bruker SMART APEXII CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0182
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            17650
_diffrn_reflns_theta_full        28.48
_diffrn_reflns_theta_max         28.48
_diffrn_reflns_theta_min         2.04
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_T_max  0.9818
_exptl_absorpt_correction_T_min  0.9649
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Bruker, 2008)'
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.316
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             320
_exptl_crystal_size_max          0.39
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.37
_refine_diff_density_min         -0.267
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.057
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     205
_refine_ls_number_reflns         3770
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.057
_refine_ls_R_factor_all          0.0452
_refine_ls_R_factor_gt           0.0391
_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^)+(0.0701P)^2^+0.1777P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1128
_refine_ls_wR_factor_ref         0.1193
_reflns_number_gt                3284
_reflns_number_total             3770
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            hg5251.cif
_cod_data_source_block           I
_cod_database_code               2236321
_cod_database_fobs_code          2236321