Formal total synthesis of triptolide.
Miller, Natalie A; Willis, Anthony C; Sherburn, Michael S; Chemical communications (Cambridge, England)  (2008) 1226–1228; doi:10.1039/b718754h

data_7102938
_publ_section_title
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 Formal total synthesis of triptolide.
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_journal_issue                   10
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              1226
_journal_page_last               1228
_journal_paper_doi               10.1039/b718754h
_journal_year                    2008
_chemical_formula_moiety         'C21 H26 O3'
_chemical_formula_sum            'C21 H26 O3'
_chemical_formula_weight         326.44
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             06-06-28
_audit_creation_method           CRYSTALS_ver_12.18
_audit_update_record
;
2006-06-29 - Report on C21 H26 O3
by Anthony C. Willis
for Natalie Miller and Mick Sherburn
2006-06-29 - passes checkcif tests with minor warnings
;
_cell_angle_alpha                90
_cell_angle_beta                 97.868(2)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   9.6828(3)
_cell_length_b                   10.5296(5)
_cell_length_c                   35.1809(15)
_cell_measurement_reflns_used    45271
_cell_measurement_temperature    200
_cell_measurement_theta_max      25
_cell_measurement_theta_min      3
_cell_volume                     3553.1(3)
_computing_cell_refinement       'Denzo/Scalepack '
_computing_data_collection       'COLLECT (Nonius BV, 1997)'
_computing_data_reduction        'Denzo/Scalepack (Otwinowski & Minor, 1997)'
_computing_molecular_graphics
;
ORTEP-II (Johnson 1976) in teXsan (MSC, 1992-1997)
;
_computing_publication_material  'CRYSTALS '
_computing_structure_refinement  'CRYSTALS (Watkin et al 2003)'
_computing_structure_solution    'SIR92 (Altomare et al, 1994)'
_diffrn_ambient_temperature      200
_diffrn_measured_fraction_theta_full 0.988
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       ' \f and \w scans with CCD '
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.093
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       41
_diffrn_reflns_limit_l_min       -41
_diffrn_reflns_number            29916
_diffrn_reflns_theta_full        25.038
_diffrn_reflns_theta_max         25.038
_diffrn_reflns_theta_min         2.560
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_T_max  0.998
_exptl_absorpt_correction_T_min  0.982
_exptl_absorpt_correction_type   integration
_exptl_absorpt_process_details
;
via Gaussian method (Coppens, 1970) implemented in maXus (2000)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.220
_exptl_crystal_density_meas      ?
_exptl_crystal_description       plate
_exptl_crystal_F_000             1408
_exptl_crystal_size_max          0.33
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.25
_refine_diff_density_min         -0.22
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.1722
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     433
_refine_ls_number_reflns         2641
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.1597
_refine_ls_R_factor_gt           0.0534
_refine_ls_shift/su_max          0.000361
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982)
[weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)]
where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax
Method = Robust Weighting (Prince, 1982)
W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^
A~i~ are:
1.91 1.87 1.51
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0771
_refine_ls_wR_factor_gt          0.0494
_refine_ls_wR_factor_ref         0.0494
_reflns_limit_h_max              11
_reflns_limit_h_min              -11
_reflns_limit_k_max              12
_reflns_limit_k_min              0
_reflns_limit_l_max              41
_reflns_limit_l_min              0
_reflns_number_gt                2641
_reflns_number_total             6212
_reflns_threshold_expression     I>1.5\s(I)
_cod_data_source_file            b718754h.txt
_cod_data_source_block           she0616
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      'P 1 21/c 1 '
_cod_database_code               7102938