Total Synthesis of the Quinone Epoxide Dimer (+)-Torreyanic Acid: Application of a Biomimetic Oxidation/Electrocyclization/Diels-Alder Dimerization Cascade1
Chaomin Li; Richard P. Johnson; John A. Porco; Journal of the American Chemical Society 125 (2003) 5095–5106; doi:10.1021/ja021396c

data_4113680
_publ_contact_author
;
     John A. Porco, Jr.
        Department of Chemistry and Center for Streamlined Synthesis
    590 Commonwealth Avenue
    Boston, MA 02215
        USA
;
_publ_contact_author_email       porco@chem.bu.edu
_publ_section_title
;
 Total Synthesis of the Quinone Epoxide Dimer (+)-Torreyanic Acid:
 Application of a Biomimetic Oxidation/Electrocyclization/Diels-Alder
 Dimerization Cascade1
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5095
_journal_page_last               5106
_journal_paper_doi               10.1021/ja021396c
_journal_volume                  125
_journal_year                    2003
_chemical_formula_sum            'C28 H33 Br O4 Si'
_chemical_formula_weight         541.54
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                82.927(2)
_cell_angle_beta                 89.152(2)
_cell_angle_gamma                73.488(2)
_cell_formula_units_Z            2
_cell_length_a                   8.0418(6)
_cell_length_b                   11.1920(9)
_cell_length_c                   15.8196(12)
_cell_measurement_temperature    173(2)
_cell_volume                     1354.41(18)
_computing_cell_refinement       SAINT+
_computing_data_collection       SMART
_computing_data_reduction        SAINT+
_computing_molecular_graphics    SHELXTL
_computing_publication_material  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 0.980
_diffrn_measured_fraction_theta_max 0.980
_diffrn_measurement_device_type  'Bruker 1K CCD'
_diffrn_measurement_method       '0.3 deg omega & phi 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  0.0204
_diffrn_reflns_av_sigmaI/netI    0.0232
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            16036
_diffrn_reflns_theta_full        28.28
_diffrn_reflns_theta_max         28.28
_diffrn_reflns_theta_min         1.91
_exptl_absorpt_coefficient_mu    1.592
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.724859
_exptl_absorpt_correction_type   SADABS
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.328
_exptl_crystal_description       block
_exptl_crystal_F_000             564
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.405
_refine_diff_density_min         -0.204
_refine_diff_density_rms         0.048
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.005
_refine_ls_hydrogen_treatment    isotropic
_refine_ls_matrix_type           full
_refine_ls_number_parameters     439
_refine_ls_number_reflns         6601
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.005
_refine_ls_R_factor_all          0.0346
_refine_ls_R_factor_gt           0.0273
_refine_ls_shift/su_max          0.126
_refine_ls_shift/su_mean         0.012
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0567P)^2^+0.0251P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0748
_refine_ls_wR_factor_ref         0.0782
_reflns_number_gt                5690
_reflns_number_total             6601
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja021396c_1.cif
_cod_data_source_block           porco2
_cod_database_code               4113680