Mechanistic Studies of UV Assisted [4 + 2] Cycloadditions in Synthetic Efforts toward Vibsanin E
Joachim Nikolai; Øystein Loe; Paulina M. Dominiak; Oksana O. Gerlitz; Jochen Autschbach; Huw M. L. Davies; Journal of the American Chemical Society 129 (2007) 10763–10772; doi:10.1021/ja072090e

data_4109836
_publ_section_title
;
 Mechanistic Studies of UV Assisted [4 + 2] Cycloadditions in Synthetic
 Efforts toward Vibsanin E
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              10763
_journal_page_last               10772
_journal_paper_doi               10.1021/ja072090e
_journal_volume                  129
_journal_year                    2007
_chemical_formula_moiety         'C20 H30 O3'
_chemical_formula_sum            'C20 H30 O3'
_chemical_formula_weight         318.44
_chemical_name_common            C20H30O3
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   difmap
_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            8
_cell_length_a                   9.9385(4)
_cell_length_b                   18.2555(7)
_cell_length_c                   18.9100(7)
_cell_measurement_reflns_used    800
_cell_measurement_temperature    90(1)
_cell_measurement_theta_max      28.30
_cell_measurement_theta_min      2.23
_cell_volume                     3430.9(2)
_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      90(1)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0445
_diffrn_reflns_av_sigmaI/netI    0.0193
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            52532
_diffrn_reflns_theta_full        28.31
_diffrn_reflns_theta_max         28.31
_diffrn_reflns_theta_min         2.15
_diffrn_standards_decay_%        none
_diffrn_standards_interval_count none
_diffrn_standards_interval_time  none
_diffrn_standards_number         none
_exptl_absorpt_coefficient_mu    0.081
_exptl_absorpt_correction_T_max  0.994
_exptl_absorpt_correction_T_min  0.954
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS v2.05'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.233
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             1392
_exptl_crystal_size_max          0.55
_exptl_crystal_size_mid          0.45
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.443
_refine_diff_density_min         -0.223
_refine_diff_density_rms         0.061
_refine_ls_extinction_coef       0.0110(7)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.084
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     213
_refine_ls_number_reflns         4268
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.084
_refine_ls_R_factor_all          0.0531
_refine_ls_R_factor_gt           0.0392
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         <0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0447P)^2^+1.8915P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0945
_refine_ls_wR_factor_ref         0.1090
_reflns_number_gt                3497
_reflns_number_total             4268
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja072090esi20070624_032713.cif
_cod_data_source_block           organic03
_cod_original_sg_symbol_Hall     -P2ac2ab
_cod_database_code               4109836