Chemoselective synthesis of tetrasubstituted furans via intramolecular Wittig reactions: mechanism and theoretical analysis.
Lee, Yu-Ting; Lee, Yen-Te; Lee, Chia-Jui; Sheu, Chia-Ning; Lin, Bo-Yu; Wang, Jeng-Han; Lin, Wenwei; Organic & biomolecular chemistry 11 (2013) 5156–5161; doi:10.1039/c3ob40858b

data_7153025
_publ_section_title
;
 Chemoselective synthesis of tetrasubstituted furans via intramolecular
 Wittig reactions: mechanism and theoretical analysis.
;
_journal_issue                   31
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              5156
_journal_page_last               5161
_journal_paper_doi               10.1039/c3ob40858b
_journal_volume                  11
_journal_year                    2013
_chemical_formula_moiety         'C36 H22 Br2 O4'
_chemical_formula_sum            'C36 H22 Br2 O4'
_chemical_formula_weight         678.36
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_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                 97.506(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   16.6326(7)
_cell_length_b                   18.9665(8)
_cell_length_c                   9.2524(4)
_cell_measurement_reflns_used    0
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      0
_cell_measurement_theta_min      0
_cell_volume                     2893.8(2)
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1986)'
_diffrn_ambient_temperature      200(2)
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.983
_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  0.0407
_diffrn_reflns_av_sigmaI/netI    0.0606
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            12941
_diffrn_reflns_theta_full        25.02
_diffrn_reflns_theta_max         25.02
_diffrn_reflns_theta_min         1.23
_exptl_absorpt_coefficient_mu    2.842
_exptl_absorpt_correction_T_max  0.8710
_exptl_absorpt_correction_T_min  0.5487
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.557
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1360
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.859
_refine_diff_density_min         -0.856
_refine_diff_density_rms         0.065
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.005
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     379
_refine_ls_number_reflns         5013
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.005
_refine_ls_R_factor_all          0.0803
_refine_ls_R_factor_gt           0.0428
_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^)+(0.0320P)^2^+2.8759P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0825
_refine_ls_wR_factor_ref         0.0977
_reflns_number_gt                3351
_reflns_number_total             5013
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3ob40858b.txt
_cod_data_source_block           a13131
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               7153025