Bioinspired Polyene Cyclization Promoted by Intermolecular Chiral Acetal-SnCl4 or Chiral N-Acetal-TiCl4: Investigation of the Mechanism and Identification of the Key Intermediates
Yu-Jun Zhao; Teck-Peng Loh; Journal of the American Chemical Society 130 (2008) 10024–10029; doi:10.1021/ja802896n

data_4108120
_publ_section_title
;
 Bioinspired Polyene Cyclization Promoted by Intermolecular Chiral
 Acetal-SnCl4 or Chiral N-Acetal-TiCl4: Investigation of the Mechanism and
 Identification of the Key Intermediates
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              10024
_journal_page_last               10029
_journal_paper_doi               10.1021/ja802896n
_journal_volume                  130
_journal_year                    2008
_chemical_formula_sum            'C24 H28 O'
_chemical_formula_weight         332.46
_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                 109.175(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.8466(4)
_cell_length_b                   14.5211(5)
_cell_length_c                   12.6067(4)
_cell_measurement_reflns_used    9043
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      30.38
_cell_measurement_theta_min      2.43
_cell_volume                     1875.45(11)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0327
_diffrn_reflns_av_sigmaI/netI    0.0280
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            26346
_diffrn_reflns_theta_full        30.46
_diffrn_reflns_theta_max         30.46
_diffrn_reflns_theta_min         1.99
_exptl_absorpt_coefficient_mu    0.070
_exptl_absorpt_correction_T_max  0.9862
_exptl_absorpt_correction_T_min  0.9828
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.177
_exptl_crystal_density_meas      0
_exptl_crystal_description       fragment
_exptl_crystal_F_000             720
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.343
_refine_diff_density_min         -0.161
_refine_diff_density_rms         0.044
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     338
_refine_ls_number_reflns         5678
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.0593
_refine_ls_R_factor_gt           0.0459
_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^)+(0.0763P)^2^+0.1977P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1231
_refine_ls_wR_factor_ref         0.1335
_reflns_number_gt                4470
_reflns_number_total             5678
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja802896n-file003.cif
_cod_data_source_block           ltp51
_cod_database_code               4108120