On the Origin of Diastereoselectivity in [2 + 2 + 2] Cycloisomerization of Chiral Triynes: Controlling Helicity of Helicene-like Compounds by Thermodynamic Factors
Petr Sehnal; Zuzana Krausová; Filip Teplý; Irena G. Stará; Ivo Starý; Lubomír Rulíšek; David Šaman; Ivana Císařová; Journal of Organic Chemistry 73 (2008) 2074–2082; doi:10.1021/jo701997p

data_4023324
_publ_section_title
;
 On the Origin of Diastereoselectivity in [2 + 2 + 2]
 Cycloisomerization of Chiral Triynes: Controlling Helicity of
 Helicene-like Compounds by Thermodynamic Factors
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              2074
_journal_page_last               2082
_journal_paper_doi               10.1021/jo701997p
_journal_volume                  73
_journal_year                    2008
_chemical_formula_sum            'C34 H28 O2'
_chemical_formula_weight         468.56
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 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            4
_cell_length_a                   8.1197(5)
_cell_length_b                   12.2354(6)
_cell_length_c                   24.5388(16)
_cell_measurement_temperature    293(2)
_cell_volume                     2437.9(2)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_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  0.0423
_diffrn_reflns_av_sigmaI/netI    0.0448
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            26463
_diffrn_reflns_theta_full        25.06
_diffrn_reflns_theta_max         25.06
_diffrn_reflns_theta_min         2.64
_exptl_absorpt_coefficient_mu    0.078
_exptl_crystal_density_diffrn    1.277
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             992
_refine_diff_density_max         0.121
_refine_diff_density_min         -0.160
_refine_diff_density_rms         0.032
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.5(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.916
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     331
_refine_ls_number_reflns         4325
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.916
_refine_ls_R_factor_all          0.0452
_refine_ls_R_factor_gt           0.0296
_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^)+(0.0387P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0605
_refine_ls_wR_factor_ref         0.0630
_reflns_number_gt                3276
_reflns_number_total             4325
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo701997p-File002.cif
_cod_data_source_block           ps180
_cod_database_code               4023324