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_7152748
_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            'C26 H33 Cl2 N O6'
_chemical_formula_weight         526.43
_chemical_name_systematic
;
?
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                93.8650(10)
_cell_angle_beta                 100.2260(10)
_cell_angle_gamma                90.9150(10)
_cell_formula_units_Z            4
_cell_length_a                   10.6090(3)
_cell_length_b                   15.8952(4)
_cell_length_c                   16.3523(4)
_cell_measurement_reflns_used    118
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      75.15
_cell_measurement_theta_min      15.71
_cell_volume                     2706.45(12)
_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 0.955
_diffrn_measured_fraction_theta_max 0.955
_diffrn_measurement_device_type  'APEX II DUO'
_diffrn_measurement_method       'omega/phi scans'
_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  0.0306
_diffrn_reflns_av_sigmaI/netI    0.0305
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            30958
_diffrn_reflns_theta_full        66.59
_diffrn_reflns_theta_max         66.59
_diffrn_reflns_theta_min         2.75
_exptl_absorpt_coefficient_mu    2.488
_exptl_absorpt_correction_T_max  0.9898
_exptl_absorpt_correction_T_min  0.7026
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.292
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1112
_exptl_crystal_size_max          0.37
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.05
_refine_diff_density_max         1.092
_refine_diff_density_min         -0.681
_refine_diff_density_rms         0.060
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     658
_refine_ls_number_reflns         9133
_refine_ls_number_restraints     13
_refine_ls_restrained_S_all      1.067
_refine_ls_R_factor_all          0.0562
_refine_ls_R_factor_gt           0.0511
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0693P)^2^+2.9890P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1364
_refine_ls_wR_factor_ref         0.1407
_reflns_number_gt                8138
_reflns_number_total             9133
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob26815a.txt
_cod_data_source_block           cu_nwn79_0m
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7152748