Four New Eremophilane Derivatives from Ligularia sagitta
Li, Ping-Lin; Zhang, Zhan-Xin; Jia, Zhong-Jian; Chemistry Letters 37 (2008) 308–; doi:10.1246/cl.2008.308

data_8000184
_publ_section_title
;
 Four New Eremophilane Derivatives from Ligularia sagitta
;
_journal_issue                   3
_journal_name_full               'Chemistry Letters'
_journal_page_first              308
_journal_paper_doi               10.1246/cl.2008.308
_journal_volume                  37
_journal_year                    2008
_chemical_formula_sum            'C22 H30 O7'
_chemical_formula_weight         406.46
_space_group_IT_number           4
_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_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 91.7740(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   7.1629(2)
_cell_length_b                   14.2956(3)
_cell_length_c                   10.1682(3)
_cell_measurement_temperature    294(2)
_cell_volume                     1040.70(5)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      294(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0127
_diffrn_reflns_av_sigmaI/netI    0.0204
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            5670
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         2.00
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_T_max  0.9886
_exptl_absorpt_correction_T_min  0.9792
_exptl_crystal_density_diffrn    1.297
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             436
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.157
_refine_diff_density_min         -0.146
_refine_diff_density_rms         0.027
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.4(7)
_refine_ls_extinction_coef       0.007(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.320
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     269
_refine_ls_number_reflns         3677
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.320
_refine_ls_R_factor_all          0.0355
_refine_ls_R_factor_gt           0.0324
_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^)+(0.0449P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0857
_refine_ls_wR_factor_ref         0.0879
_reflns_number_gt                3454
_reflns_number_total             3677
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            37-308sup1.cif
_cod_data_source_block           p21
_cod_database_code               8000184