A hypervalent iodine-mediated spirocyclization of 2-(4-hydroxybenzamido)acrylates - unexpected formation of δ-spirolactones.
Hempel, Christian; Weckenmann, Nicole M.; Maichle-Moessmer, C; Nachtsheim, Boris J.; Organic & biomolecular chemistry 10 (2012) 9325–9329; doi:10.1039/c2ob26815a

data_7152749
_publ_section_title
;
 A hypervalent iodine-mediated spirocyclization of
 2-(4-hydroxybenzamido)acrylates - unexpected formation of
 \d-spirolactones.
;
_journal_issue                   47
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              9325
_journal_page_last               9329
_journal_paper_doi               10.1039/c2ob26815a
_journal_volume                  10
_journal_year                    2012
_chemical_formula_sum            'C17 H13 N O4'
_chemical_formula_weight         295.28
_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            8
_cell_length_a                   20.8667(4)
_cell_length_b                   5.20470(10)
_cell_length_c                   26.1797(5)
_cell_measurement_reflns_used    127
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      130.9
_cell_measurement_theta_min      40.8
_cell_volume                     2843.24(9)
_computing_cell_refinement       SAINT
_computing_data_collection       COSMO
_computing_data_reduction        SAINT
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'APEX II DUO'
_diffrn_measurement_method       omega/phi
_diffrn_radiation_monochromator  multilayer
_diffrn_radiation_source         'ImuS-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0363
_diffrn_reflns_av_sigmaI/netI    0.0347
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            21209
_diffrn_reflns_theta_full        66.64
_diffrn_reflns_theta_max         66.64
_diffrn_reflns_theta_min         3.38
_exptl_absorpt_coefficient_mu    0.823
_exptl_absorpt_correction_T_max  0.9741
_exptl_absorpt_correction_T_min  0.7529
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.380
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1232
_exptl_crystal_size_max          0.37
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.290
_refine_diff_density_min         -0.216
_refine_diff_density_rms         0.033
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.46(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.055
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     397
_refine_ls_number_reflns         4961
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.055
_refine_ls_R_factor_all          0.0333
_refine_ls_R_factor_gt           0.0317
_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^)+(0.0363P)^2^+0.8759P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0811
_refine_ls_wR_factor_ref         0.0823
_reflns_number_gt                4784
_reflns_number_total             4961
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob26815a.txt
_cod_data_source_block           cu_nwn89_0ma
_cod_original_sg_symbol_H-M      Pna21
_cod_database_code               7152749