Icacinlactone H and Icacintrichantholide from the Tuber of Icacina trichantha.
Zhao, Ming; Onakpa, Monday M.; Santarsiero, Bernard D.; Huang, Xiao-Jun; Zhang, Xiao-Qi; Chen, Jia; Cheng, Jian-Jun; Longnecker, Richard; Che, Chun-Tao; Organic letters 17 (2015) 3834–3837; doi:10.1021/acs.orglett.5b01806

data_1529875
_publ_section_title
;
 Icacinlactone H and Icacintrichantholide from the Tuber of Icacina
 trichantha.
;
_journal_issue                   15
_journal_name_full               'Organic letters'
_journal_page_first              3834
_journal_page_last               3837
_journal_paper_doi               10.1021/acs.orglett.5b01806
_journal_volume                  17
_journal_year                    2015
_chemical_formula_moiety         'C20 H20 O7'
_chemical_formula_sum            'C20 H20 O7'
_chemical_formula_weight         372.36
_chemical_name_common            Icacinlactone
_space_group_crystal_system      orthorhombic
_space_group_IT_number           18
_space_group_name_Hall           'P 2 2ab'
_space_group_name_H-M_alt        'P 21 21 2'
_symmetry_space_group_name_Hall  'P 2 2ab'
_symmetry_space_group_name_H-M   'P 21 21 2'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.8018(3)
_cell_length_b                   20.5957(9)
_cell_length_c                   12.4023(5)
_cell_measurement_temperature    100.0(1)
_cell_volume                     1737.41(13)
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      100.0(1)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker SMART/APEXII'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0332
_diffrn_reflns_av_unetI/netI     0.0204
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            15297
_diffrn_reflns_point_group_measured_fraction_full 0.995
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.234
_diffrn_reflns_theta_min         3.564
_exptl_absorpt_coefficient_mu    0.907
_exptl_absorpt_correction_T_max  0.8574
_exptl_absorpt_correction_T_min  0.7073
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'SADABS 2014/4'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.528
_exptl_crystal_description       block
_exptl_crystal_F_000             784
_exptl_crystal_size_max          0.432
_exptl_crystal_size_mid          0.368
_exptl_crystal_size_min          0.184
_refine_diff_density_max         0.685
_refine_diff_density_min         -.627
_refine_diff_density_rms         0.134
_refine_ls_abs_structure_details
;
 Flack x determined using 1306 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
 Parsons z = 0.18(3),
 G = 0.93(9), Hooft y = 0.04(4)
 P2(true) = 1.000, P3(true) = 1.000, 
 P3(racemic twin) = 9E-26, P3(false) = 5E-106
;
_refine_ls_abs_structure_Flack   0.17(5)
_refine_ls_extinction_coef       0.062(5)
_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   1.221
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     253
_refine_ls_number_reflns         3159
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.221
_refine_ls_R_factor_all          0.0721
_refine_ls_R_factor_gt           0.0721
_refine_ls_shift/su_max          0.007
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0677P)^2^+5.1948P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1924
_refine_ls_wR_factor_ref         0.1924
_reflns_Friedel_coverage         0.705
_reflns_Friedel_fraction_full    0.989
_reflns_Friedel_fraction_max     0.984
_reflns_number_gt                3157
_reflns_number_total             3159
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol5b01806_si_002.cif
_cod_data_source_block           UIC2014MingIC5
_cod_database_code               1529875
_shelxl_version_number           2013-3
_shelx_res_checksum              7598
_shelx_hkl_checksum              11184
_shelx_fab_checksum              97285