A hydrogen peroxide based access to qinghaosu (artemisinin).
Hao, Hong-Dong; Li, Yun; Han, Wei-Bo; Wu, Yikang; Organic letters 13 (2011) 4212–4215; doi:10.1021/ol2015434

data_1502321
_publ_section_title
;
 A hydrogen peroxide based access to qinghaosu (artemisinin).
;
_journal_issue                   16
_journal_name_full               'Organic letters'
_journal_page_first              4212
_journal_page_last               4215
_journal_paper_doi               10.1021/ol2015434
_journal_volume                  13
_journal_year                    2011
_chemical_formula_sum            'C12 H18 O4'
_chemical_formula_weight         226.26
_space_group_IT_number           56
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ab 2ac'
_symmetry_space_group_name_H-M   'P c c n'
_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                   27.989(3)
_cell_length_b                   9.0736(9)
_cell_length_c                   9.4414(10)
_cell_measurement_reflns_used    2375
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      55.193
_cell_measurement_theta_min      4.707
_cell_volume                     2397.7(4)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.1176
_diffrn_reflns_av_sigmaI/netI    0.0766
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -33
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            11703
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         2.36
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.0934
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.254
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             976
_exptl_crystal_size_max          0.398
_exptl_crystal_size_mid          0.357
_exptl_crystal_size_min          0.301
_refine_diff_density_max         0.233
_refine_diff_density_min         -0.202
_refine_diff_density_rms         0.062
_refine_ls_extinction_coef       0.0028(4)
_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   1.026
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     147
_refine_ls_number_reflns         2226
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.026
_refine_ls_R_factor_all          0.0886
_refine_ls_R_factor_gt           0.0607
_refine_ls_shift/su_max          0.005
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1058P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1641
_refine_ls_wR_factor_ref         0.1818
_reflns_number_gt                1498
_reflns_number_total             2226
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol2015434_si_002.cif
_cod_data_source_block           cd201278
_cod_depositor_comments
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The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      Pccn
_cod_database_code               1502321