Transannular rearrangement of activated 2,5-diketopiperazines: a key route to original scaffolds
Farran, Daniel; Parrot, Isabelle; Toupet, Loïc; Martinez, Jean; Dewynter, Georges; Organic & Biomolecular Chemistry 6 (2008) 3989–3996; doi:10.1039/b810352f

data_7151007
_publ_section_title
;
 Transannular rearrangement of activated 2,5-diketopiperazines: a key
 route to original scaffolds
;
_journal_issue                   21
_journal_name_full               'Organic &amp; Biomolecular Chemistry'
_journal_page_first              3989
_journal_page_last               3996
_journal_paper_doi               10.1039/b810352f
_journal_volume                  6
_journal_year                    2008
_chemical_formula_sum            'C24 H24 N2 O4'
_chemical_formula_weight         404.45
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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            4
_cell_length_a                   10.4911(5)
_cell_length_b                   12.2289(6)
_cell_length_c                   16.1319(7)
_cell_measurement_temperature    110(2)
_cell_volume                     2069.64(17)
_computing_cell_refinement
'CrysAlis RED, Oxford Diffraction Ltd.,Version 1.171.26'
_computing_data_collection
'CrysAlis CCD, Oxford Diffraction Ltd.,Version 1.171.26'
_computing_data_reduction
'CrysAlis RED, Oxford Diffraction Ltd.,Version 1.171.26'
_computing_molecular_graphics    'PLATON_(Spek, 1998)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR-97_(Altomare & al., 1998)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 19.64
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'CCD Saphire 3 Xcalibur'
_diffrn_measurement_method       'omega scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0229
_diffrn_reflns_av_sigmaI/netI    0.0314
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            15200
_diffrn_reflns_theta_full        26.99
_diffrn_reflns_theta_max         26.99
_diffrn_reflns_theta_min         2.56
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.298
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             856
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.202
_refine_diff_density_min         -0.150
_refine_diff_density_rms         0.036
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.0(6)
_refine_ls_extinction_coef       0.0105(13)
_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   0.724
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     272
_refine_ls_number_reflns         4503
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.724
_refine_ls_R_factor_all          0.0351
_refine_ls_R_factor_gt           0.0267
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0722P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0697
_refine_ls_wR_factor_ref         0.0728
_reflns_number_gt                3815
_reflns_number_total             4503
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b810352f.txt
_cod_data_source_block           df405revu
_cod_depositor_comments
;
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_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               7151007