Cycloaddition of homochiral dihydroimidazoles: a 1,3-dipolar cycloaddition route to optically active pyrrolo[1,2-a]imidazoles.
Jones, Raymond C. F.; Howard, Kevin J.; Snaith, John S.; Blake, Alexander J.; Li, Wang-Shei; Steel, Peter J.; Organic & biomolecular chemistry 9 (2011) 297–306; doi:10.1039/c0ob00529k

data_7153082
_publ_section_title
;
 Cycloaddition of homochiral dihydroimidazoles: a 1,3-dipolar
 cycloaddition route to optically active pyrrolo[1,2-a]imidazoles.
;
_journal_issue                   1
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              297
_journal_page_last               306
_journal_paper_doi               10.1039/c0ob00529k
_journal_volume                  9
_journal_year                    2011
_chemical_formula_sum            'C27 H34 N2 O4'
_chemical_formula_weight         450.56
_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                   8.0460(10)
_cell_length_b                   14.280(2)
_cell_length_c                   22.646(3)
_cell_measurement_reflns_used    51
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      15
_cell_measurement_theta_min      10
_cell_volume                     2602.0(6)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  P4
_diffrn_measurement_method       '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  0.2758
_diffrn_reflns_av_sigmaI/netI    0.0609
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2631
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.30
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 100
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.077
_exptl_absorpt_correction_T_max  0.9773
_exptl_absorpt_correction_T_min  0.9481
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.150
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             968
_exptl_crystal_size_max          0.70
_exptl_crystal_size_mid          0.59
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.141
_refine_diff_density_min         -0.127
_refine_diff_density_rms         0.029
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   9(2)
_refine_ls_extinction_coef       0.0067(12)
_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   0.807
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     299
_refine_ls_number_reflns         2620
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.807
_refine_ls_R_factor_all          0.0854
_refine_ls_R_factor_gt           0.0418
_refine_ls_shift/su_max          0.007
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0601P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0939
_refine_ls_wR_factor_ref         0.1034
_reflns_number_gt                1393
_reflns_number_total             2620
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c0ob00529k.txt
_cod_data_source_block           3js2
_cod_depositor_comments
'Adding full bibliography for 7153082--7153084.cif.'
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7153082