Cope rearrangement versus a novel tandem retro-Diels-Alder-Diels-Alder reaction with role reversal.
Su, Kuan-Jen; Mieusset, Jean-Luc; Arion, Vladimir B.; Brecker, Lothar; Brinker, Udo H.; Organic letters 9 (2007) 113–115; doi:10.1021/ol0626793

data_1505253
_publ_section_title
;
 Cope rearrangement versus a novel tandem retro-Diels-Alder-Diels-Alder
 reaction with role reversal.
;
_journal_issue                   1
_journal_name_full               'Organic letters'
_journal_page_first              113
_journal_page_last               115
_journal_paper_doi               10.1021/ol0626793
_journal_volume                  9
_journal_year                    2007
_chemical_formula_sum            'C11 H12 Br2'
_chemical_formula_weight         304.03
_chemical_name_systematic
; 
4,5exo-dibromo-endo-tricyclo[6.2.1.0^2,7^]undeca-3,9-diene   
;
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 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            8
_cell_length_a                   13.0891(12)
_cell_length_b                   10.9312(9)
_cell_length_c                   14.5270(13)
_cell_measurement_temperature    100(2)
_cell_volume                     2078.5(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_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  0.0461
_diffrn_reflns_av_sigmaI/netI    0.0312
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            42389
_diffrn_reflns_theta_full        29.12
_diffrn_reflns_theta_max         29.12
_diffrn_reflns_theta_min         2.33
_exptl_absorpt_coefficient_mu    7.749
_exptl_absorpt_correction_T_max  0.3360
_exptl_absorpt_correction_T_min  0.1476
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_density_diffrn    1.943
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1184
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.18
_refine_diff_density_max         1.362
_refine_diff_density_min         -0.830
_refine_diff_density_rms         0.117
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.354(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.039
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     236
_refine_ls_number_reflns         5584
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.039
_refine_ls_R_factor_all          0.0387
_refine_ls_R_factor_gt           0.0277
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0386P)^2^+0.6894P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0627
_refine_ls_wR_factor_ref         0.0669
_reflns_number_gt                4868
_reflns_number_total             5584
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol0626793si20061102_084636.cif
_cod_data_source_block           KUSU70
_cod_original_sg_symbol_H-M      Pna2(1)
_cod_database_code               1505253