An efficient synthesis of trisubstituted oxazoles via chemoselective O-acylations and intramolecular Wittig reactions
Yi-Ling Tsai; Yu-Shiou Fan; Chia-Jui Lee; Chan-Hui Huang; Utpal Das; Wenwei Lin; Chem.Commun. 49 (2013) 10266–; doi:10.1039/c3cc45883k

data_7109966
_publ_section_title
;
 An efficient synthesis of trisubstituted oxazoles via chemoselective
 O-acylations and intramolecular Wittig reactions
;
_journal_name_full               Chem.Commun.
_journal_page_first              10266
_journal_paper_doi               10.1039/c3cc45883k
_journal_volume                  49
_journal_year                    2013
_chemical_formula_moiety         'C21 H14 Br N O'
_chemical_formula_sum            'C21 H14 Br N O'
_chemical_formula_weight         376.24
_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                   20.1931(14)
_cell_length_b                   20.0328(12)
_cell_length_c                   3.9753(3)
_cell_measurement_reflns_used    0
_cell_measurement_temperature    200(2)
_cell_measurement_theta_max      0
_cell_measurement_theta_min      0
_cell_volume                     1608.11(19)
_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 0.997
_diffrn_measured_fraction_theta_max 0.997
_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  0.0512
_diffrn_reflns_av_sigmaI/netI    0.0487
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       2
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            10631
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         2.02
_exptl_absorpt_coefficient_mu    2.563
_exptl_absorpt_correction_T_max  0.9505
_exptl_absorpt_correction_T_min  0.3852
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.554
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             760
_exptl_crystal_size_max          0.46
_exptl_crystal_size_mid          0.09
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.803
_refine_diff_density_min         -0.372
_refine_diff_density_rms         0.070
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.21(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.065
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         2301
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.065
_refine_ls_R_factor_all          0.0554
_refine_ls_R_factor_gt           0.0434
_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^)+(0.0416P)^2^+2.2617P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0959
_refine_ls_wR_factor_ref         0.1002
_reflns_number_gt                1943
_reflns_number_total             2301
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c3cc45883k.txt
_cod_data_source_block           a12609
_cod_database_code               7109966