Intramolecular [1 + 2] and [3 + 2] Cycloaddition Reactions of Cyclopropenone Ketals
Paresma R. Patel; Dale L. Boger; Journal of the American Chemical Society 132 (2010) 8527–8529; doi:10.1021/ja103933n

data_4102604
_publ_section_title
;
 Intramolecular [1 + 2] and [3 + 2] Cycloaddition Reactions of
 Cyclopropenone Ketals
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              8527
_journal_page_last               8529
_journal_paper_doi               10.1021/ja103933n
_journal_volume                  132
_journal_year                    2010
_chemical_formula_sum            'C20 H24 O3'
_chemical_formula_weight         312.39
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 122.21(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   30.462(6)
_cell_length_b                   8.0445(16)
_cell_length_c                   16.349(3)
_cell_measurement_reflns_used    4285
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      26.2
_cell_measurement_theta_min      2.5
_cell_volume                     3389.8(16)
_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, 1997)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0286
_diffrn_reflns_av_sigmaI/netI    0.0257
_diffrn_reflns_limit_h_max       36
_diffrn_reflns_limit_h_min       -36
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            11922
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.58
_diffrn_standards_decay_%        1
_exptl_absorpt_coefficient_mu    0.081
_exptl_absorpt_correction_T_max  0.9880
_exptl_absorpt_correction_T_min  0.9809
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1999)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.224
_exptl_crystal_density_meas      0
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Parallalepiped
_exptl_crystal_F_000             1344
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.439
_refine_diff_density_min         -0.268
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.128
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     211
_refine_ls_number_reflns         2974
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.128
_refine_ls_R_factor_all          0.0870
_refine_ls_R_factor_gt           0.0674
_refine_ls_shift/su_max          0.027
_refine_ls_shift/su_mean         0.004
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0700P)^2^+4.4000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1712
_refine_ls_wR_factor_ref         0.1826
_reflns_number_gt                2277
_reflns_number_total             2974
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja103933n_si_008.cif
_cod_data_source_block           prp91
_cod_original_cell_volume        3389.9(12)
_cod_database_code               4102604