Structural characterization of an enantiomerically pure amino acid imidazolide and direct formation of the beta-lactam nucleus from an alpha-amino acid.
Gerstenberger, Brian S.; Lin, Jinzhen; Mimieux, Yvette S.; Brown, Lauren E.; Oliver, Allen G.; Konopelski, Joseph P.; Organic letters 10 (2008) 369–372; doi:10.1021/ol7025922

data_1504481
_publ_section_title
;
 Structural characterization of an enantiomerically pure amino acid
 imidazolide and direct formation of the beta-lactam nucleus from an
 alpha-amino acid.
;
_journal_issue                   3
_journal_name_full               'Organic letters'
_journal_page_first              369
_journal_page_last               372
_journal_paper_doi               10.1021/ol7025922
_journal_volume                  10
_journal_year                    2008
_chemical_absolute_configuration rmad
_chemical_formula_moiety         'C44 H38 N2 O3'
_chemical_formula_sum            'C44 H38 N2 O3'
_chemical_formula_weight         642.76
_space_group_IT_number           144
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'P 31'
_symmetry_space_group_name_H-M   'P 31'
_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                120.00
_cell_formula_units_Z            9
_cell_length_a                   23.562(3)
_cell_length_b                   23.562(3)
_cell_length_c                   16.129(3)
_cell_measurement_reflns_used    45212
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      68.2
_cell_measurement_theta_min      6.7
_cell_volume                     7755(2)
_computing_cell_refinement       'Rigaku d*trek'
_computing_data_collection       'Rigaku d*trek'
_computing_data_reduction        'Rigaku d*trek'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'Rigaku RAXIS-RAPID'
_diffrn_measurement_method       \w-scans
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54180
_diffrn_reflns_av_R_equivalents  0.0437
_diffrn_reflns_av_sigmaI/netI    0.0982
_diffrn_reflns_limit_h_max       26
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            48748
_diffrn_reflns_theta_full        68.21
_diffrn_reflns_theta_max         68.21
_diffrn_reflns_theta_min         6.65
_exptl_absorpt_coefficient_mu    0.608
_exptl_absorpt_correction_T_max  0.9197
_exptl_absorpt_correction_T_min  0.6756
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'Sheldrick, 2001'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.239
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             3060
_exptl_crystal_size_max          0.70
_exptl_crystal_size_mid          0.18
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.174
_refine_diff_density_min         -0.191
_refine_diff_density_rms         0.039
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.04(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.814
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1325
_refine_ls_number_reflns         18012
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.814
_refine_ls_R_factor_all          0.0544
_refine_ls_R_factor_gt           0.0385
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0182P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0500
_refine_ls_wR_factor_ref         0.0548
_reflns_number_gt                13173
_reflns_number_total             18012
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol7025922-file001.cif
_cod_data_source_block           lbc1a
_cod_database_code               1504481