Understanding the Fate of the Oxyallyl Cation following Nazarov Electrocyclization: Sequential Wagner-Meerwein Migrations and the Synthesis of Spirocyclic Cyclopentenones
Jie Huang; David Leboeuf; Alison J. Frontier; Journal of the American Chemical Society 133 (2011) 6307–6317; doi:10.1021/ja111504w

data_4106027
_publ_section_title
;
 Understanding the Fate of the Oxyallyl Cation following Nazarov
 Electrocyclization: Sequential Wagner-Meerwein Migrations and the
 Synthesis of Spirocyclic Cyclopentenones
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              6307
_journal_page_last               6317
_journal_paper_doi               10.1021/ja111504w
_journal_volume                  133
_journal_year                    2011
_chemical_formula_moiety         'C21 H28 O7'
_chemical_formula_sum            'C21 H28 O7'
_chemical_formula_weight         392.43
_chemical_name_common            frojh02
_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                 109.406(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.2094(10)
_cell_length_b                   28.466(3)
_cell_length_c                   8.8206(10)
_cell_measurement_reflns_used    3807
_cell_measurement_temperature    100.0(1)
_cell_measurement_theta_max      32.84
_cell_measurement_theta_min      2.63
_cell_volume                     1944.2(4)
_computing_cell_refinement       'SAINT (Bruker, 2006)'
_computing_data_collection       'APEX2 (Bruker, 2006)'
_computing_data_reduction        'SAINT (Bruker, 2006)'
_computing_molecular_graphics    'SHELXTL (Bruker, 2000)'
_computing_publication_material  'SHELXTL (Bruker, 2000)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100.0(1)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_measurement_device_type  'Bruker SMART APEX II CCD Platform'
_diffrn_measurement_method       'area detector, /w scans per f'
_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  0.0348
_diffrn_reflns_av_sigmaI/netI    0.0293
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       42
_diffrn_reflns_limit_k_min       -42
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            34568
_diffrn_reflns_theta_full        32.56
_diffrn_reflns_theta_max         32.56
_diffrn_reflns_theta_min         2.55
_exptl_absorpt_coefficient_mu    0.100
_exptl_absorpt_correction_T_max  0.9881
_exptl_absorpt_correction_T_min  0.9754
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Blessing, 1995)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.341
_exptl_crystal_description       block
_exptl_crystal_F_000             840
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.494
_refine_diff_density_min         -0.215
_refine_diff_density_rms         0.054
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.016
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     365
_refine_ls_number_reflns         7007
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.016
_refine_ls_R_factor_all          0.0616
_refine_ls_R_factor_gt           0.0454
_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^)+(0.0639P)^2^+0.5358P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1135
_refine_ls_wR_factor_ref         0.1227
_reflns_number_gt                5528
_reflns_number_total             7007
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja111504w_si_001.cif
_cod_data_source_block           frojh02
_cod_database_code               4106027