Acid Catalyzed Ring Transformation of Benzofurans to Tri- and Tetrasubstituted Furans
Seema Dhiman; S. S. V. Ramasastry; Journal of Organic Chemistry 78 (2013) 10427–10436; doi:10.1021/jo4018233

data_4028687
_publ_section_title
;
 Acid Catalyzed Ring Transformation of Benzofurans to Tri- and
 Tetrasubstituted Furans
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              10427
_journal_page_last               10436
_journal_paper_doi               10.1021/jo4018233
_journal_volume                  78
_journal_year                    2013
_chemical_formula_moiety         'C16 H18 O3'
_chemical_formula_sum            'C16 H18 O3'
_chemical_formula_weight         258.30
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90
_cell_angle_beta                 93.907(7)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.3627(10)
_cell_length_b                   16.577(2)
_cell_length_c                   11.7672(16)
_cell_measurement_reflns_used    4501
_cell_measurement_temperature    296.(2)
_cell_measurement_theta_max      24.3164
_cell_measurement_theta_min      2.4572
_cell_volume                     1432.9(3)
_computing_cell_refinement       'SAINT V7.68A (Bruker AXS, 2009)'
_computing_data_collection       'APEX2 (Bruker)'
_computing_data_reduction        'SAINT V7.68A (Bruker AXS, 2009)'
_computing_molecular_graphics    'SHELXTL (Bruker AXS)'
_computing_publication_material  'SHELXTL (Bruker AXS)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296.(2)
_diffrn_detector_area_resol_mean 8.3333
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'Bruker Kappa APEX II'
_diffrn_measurement_method       'phi nad omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0346
_diffrn_reflns_av_sigmaI/netI    0.0275
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            12361
_diffrn_reflns_theta_full        25.06
_diffrn_reflns_theta_max         25.06
_diffrn_reflns_theta_min         2.13
_diffrn_source                   'sealed tube'
_diffrn_source_type              'fine focus'
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  0.7452
_exptl_absorpt_correction_T_min  0.6904
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2008/1 (Bruker AXS)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.197
_exptl_crystal_description       block
_exptl_crystal_F_000             552
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.550
_refine_diff_density_min         -0.322
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.045
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     176
_refine_ls_number_reflns         2513
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.045
_refine_ls_R_factor_all          0.0870
_refine_ls_R_factor_gt           0.0670
_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^)+(0.1231P)^2^+0.6089P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2004
_refine_ls_wR_factor_ref         0.2224
_reflns_number_gt                1849
_reflns_number_total             2513
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo4018233_si_002_2.cif
_cod_data_source_block           1
_cod_database_code               4028687