Acid-catalysed formation of tricyclic N,S-acetals in imidazolinone series based on the use of the unprecedented N-acyliminium ion cascade reaction involving transposition, heterocyclisation and pi-cyclisation.
Pesquet, Anthony; Daïch, Adam; Decroix, Bernard; Van Hijfte, Luc; Organic & biomolecular chemistry 3 (2005) 3937–3947; doi:10.1039/b508214e

data_7150256
_publ_section_title
;
 Acid-catalysed formation of tricyclic N,S-acetals in imidazolinone
 series based on the use of the unprecedented N-acyliminium ion cascade
 reaction involving transposition, heterocyclisation and
 pi-cyclisation.
;
_journal_issue                   21
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              3937
_journal_page_last               3947
_journal_paper_doi               10.1039/b508214e
_journal_volume                  3
_journal_year                    2005
_chemical_formula_sum            'C12 H14 N2 O S'
_chemical_formula_weight         234.31
_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                 103.69(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.569(4)
_cell_length_b                   18.652(2)
_cell_length_c                   8.388(2)
_cell_measurement_temperature    293(2)
_cell_volume                     1150.6(7)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(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     0.71069
_diffrn_reflns_av_R_equivalents  0.0184
_diffrn_reflns_av_sigmaI/netI    0.0325
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            2687
_diffrn_reflns_theta_full        26.97
_diffrn_reflns_theta_max         26.97
_diffrn_reflns_theta_min         2.18
_exptl_absorpt_coefficient_mu    0.261
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.353
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             496
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.274
_refine_diff_density_min         -0.214
_refine_diff_density_rms         0.040
_refine_ls_extinction_coef       0.009(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.043
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     149
_refine_ls_number_reflns         2505
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.043
_refine_ls_R_factor_all          0.0555
_refine_ls_R_factor_gt           0.0358
_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^)+(0.0571P)^2^+0.0458P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0944
_refine_ls_wR_factor_ref         0.0996
_reflns_number_gt                1868
_reflns_number_total             2505
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b508214e.txt
_cod_data_source_block           cap
_cod_original_sg_symbol_H-M      P21/c
_cod_database_code               7150256