Diastereoselective Synthesis of Diketopiperazine Bis-α,β-epoxides
Shin Ando; Amy L. Grote; Kazunori Koide; Journal of Organic Chemistry 76 (2011) 1155–1158; doi:10.1021/jo102096d

data_4026042
_publ_section_title
;
 Diastereoselective Synthesis of Diketopiperazine Bis-\a,\b-epoxides
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              1155
_journal_page_last               1158
_journal_paper_doi               10.1021/jo102096d
_journal_volume                  76
_journal_year                    2011
_chemical_absolute_configuration unk
_chemical_formula_sum            'C20 H18 N2 O4'
_chemical_formula_weight         350.36
_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                   8.491(6)
_cell_length_b                   9.669(7)
_cell_length_c                   20.460(14)
_cell_measurement_reflns_used    256
_cell_measurement_temperature    203(2)
_cell_measurement_theta_max      11.28
_cell_measurement_theta_min      2.33
_cell_volume                     1680(2)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_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      203(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  0.3785
_diffrn_reflns_av_sigmaI/netI    0.2244
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            11651
_diffrn_reflns_theta_full        24.00
_diffrn_reflns_theta_max         24.00
_diffrn_reflns_theta_min         1.99
_exptl_absorpt_coefficient_mu    0.098
_exptl_absorpt_correction_T_max  0.9990
_exptl_absorpt_correction_T_min  0.9826
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker Sadabs'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.385
_exptl_crystal_description       needle
_exptl_crystal_F_000             736
_exptl_crystal_size_max          0.18
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.275
_refine_diff_density_min         -0.261
_refine_diff_density_rms         0.059
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.891
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     235
_refine_ls_number_reflns         1541
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.891
_refine_ls_R_factor_all          0.1927
_refine_ls_R_factor_gt           0.0868
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0780P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1815
_refine_ls_wR_factor_ref         0.2213
_reflns_number_gt                710
_reflns_number_total             1541
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo102096d_si_001.cif
_cod_data_source_block           sa4204s
_cod_database_code               4026042