5-Endo-dig electrophilic cyclization of 1,4-disubstituted but-3-yn-1-ones: regiocontrolled synthesis of 2,5-disubstituted 3-bromo- and 3-iodofurans.
Sniady, Adam; Wheeler, Kraig A.; Dembinski, Roman; Organic letters 7 (2005) 1769–1772; doi:10.1021/ol050372i

data_1506555
_publ_section_title
;
 5-Endo-dig electrophilic cyclization of 1,4-disubstituted
 but-3-yn-1-ones: regiocontrolled synthesis of 2,5-disubstituted 3-bromo-
 and 3-iodofurans.
;
_journal_issue                   9
_journal_name_full               'Organic letters'
_journal_page_first              1769
_journal_page_last               1772
_journal_paper_doi               10.1021/ol050372i
_journal_volume                  7
_journal_year                    2005
_chemical_formula_moiety         'C20 H18 Br Cl O'
_chemical_formula_sum            'C20 H18 Br Cl O'
_chemical_formula_weight         389.69
_chemical_name_systematic
; 
 3-Bromo-5-(4-chlorohenyl)-2-(4-tertbutylphenyl)furan 
;
_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            4
_cell_length_a                   27.093(4)
_cell_length_b                   6.3920(13)
_cell_length_c                   10.5470(7)
_cell_measurement_reflns_used    24
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      24.655
_cell_measurement_theta_min      21.293
_cell_volume                     1826.5(5)
_computing_cell_refinement       'XSCANS (Bruker, 1999)'
_computing_data_collection       'XSCANS (Bruker, 1999)'
_computing_data_reduction        'XSCANS (Bruker, 1999)'
_computing_molecular_graphics    'X-SEED (Barbour, 2001)'
_computing_publication_material  'X-SEED (Barbour, 2001)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Siemens P4'
_diffrn_measurement_method       '\q/2\q\ 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  0.0291
_diffrn_reflns_av_sigmaI/netI    0.0666
_diffrn_reflns_limit_h_max       32
_diffrn_reflns_limit_h_min       -1
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -1
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -1
_diffrn_reflns_number            2425
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         2.45
_diffrn_standards_decay_%        8.1
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    2.398
_exptl_absorpt_correction_T_max  0.7954
_exptl_absorpt_correction_T_min  0.1854
_exptl_absorpt_correction_type   psi-scan
_exptl_absorpt_process_details   'North et al. Acta Cryst. 1968, A24, 351-359.'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.417
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'transparent rod'
_exptl_crystal_F_000             792
_exptl_crystal_size_max          0.96
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.311
_refine_diff_density_min         -0.301
_refine_diff_density_rms         0.049
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.00(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.019
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     212
_refine_ls_number_reflns         1963
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.019
_refine_ls_R_factor_all          0.1168
_refine_ls_R_factor_gt           0.0502
_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^)+(0.0421P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0877
_refine_ls_wR_factor_ref         0.1065
_reflns_number_gt                1085
_reflns_number_total             1963
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol050372isi20050313_053636.cif
_cod_data_source_block           c:\q04
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_Hall     'P n a 21'
_cod_database_code               1506555