Transtaganolides A-D: novel metabolites from Thapsia transtagana.
Saouf, Abderrahmane; Guerra, Francisco M.; Rubal, Juan J.; Moreno-Dorado, F Javier; Akssira, Mohamed; Mellouki, Fouad; López, Matías; Pujadas, Antonio J.; Jorge, Zacarías D; Massanet, Guillermo M.; Organic letters 7 (2005) 881–884; doi:10.1021/ol047421w

data_1506455
_publ_section_title
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 Transtaganolides A-D: novel metabolites from Thapsia transtagana.
;
_journal_issue                   5
_journal_name_full               'Organic letters'
_journal_page_first              881
_journal_page_last               884
_journal_paper_doi               10.1021/ol047421w
_journal_volume                  7
_journal_year                    2005
_chemical_formula_sum            'C20 H22 O6'
_chemical_formula_weight         358.38
_space_group_IT_number           79
_symmetry_cell_setting           tetragonal
_symmetry_space_group_name_Hall  'I 4'
_symmetry_space_group_name_H-M   'I 4'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   19.327(9)
_cell_length_b                   19.327(9)
_cell_length_c                   9.814(6)
_cell_measurement_temperature    293(2)
_cell_volume                     3666(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Giacovazzo et atl., 1999)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.943
_diffrn_measured_fraction_theta_max 0.943
_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  0.0407
_diffrn_reflns_av_sigmaI/netI    0.0421
_diffrn_reflns_limit_h_max       25
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       0
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            5741
_diffrn_reflns_theta_full        28.56
_diffrn_reflns_theta_max         28.56
_diffrn_reflns_theta_min         2.98
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.299
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             1520
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.197
_refine_diff_density_min         -0.189
_refine_diff_density_rms         0.035
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0(10)
_refine_ls_extinction_coef       0.0000(19)
_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   1.044
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     236
_refine_ls_number_reflns         2334
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.043
_refine_ls_R_factor_all          0.0741
_refine_ls_R_factor_gt           0.0575
_refine_ls_shift/su_max          0.006
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0827P)^2^+0.7814P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1348
_refine_ls_wR_factor_ref         0.1435
_reflns_number_gt                1910
_reflns_number_total             2334
_reflns_threshold_expression     >4sigma(I)
_cod_data_source_file            ol047421wsi20041216_081214.cif
_cod_data_source_block           Transtaga2
_cod_original_sg_symbol_H-M      I4
_cod_database_code               1506455