Exploration of Cascade Cyclizations Terminated by Tandem Aromatic Substitution: Total Synthesis of (+)-Schweinfurthin A
Joseph J. Topczewski; John G. Kodet; David F. Wiemer; Journal of Organic Chemistry 76 (2011) 909–919; doi:10.1021/jo1022102

data_4026015
_publ_section_title
;
 Exploration of Cascade Cyclizations Terminated by Tandem Aromatic
 Substitution: Total Synthesis of (+)-Schweinfurthin A
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              909
_journal_page_last               919
_journal_paper_doi               10.1021/jo1022102
_journal_volume                  76
_journal_year                    2011
_chemical_formula_moiety         'C20 H26 O5'
_chemical_formula_sum            'C20 H26 O5'
_chemical_formula_weight         346.41
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 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                   20.663(3)
_cell_length_b                   14.7908(16)
_cell_length_c                   6.0694(7)
_cell_measurement_reflns_used    8672
_cell_measurement_temperature    190(2)
_cell_measurement_theta_max      27.9
_cell_measurement_theta_min      1.0
_cell_volume                     1854.9(4)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor,1997)'
_computing_data_collection       'Collect (Nonius BV, 1997-2000)'
_computing_data_reduction
'HKL Denzo, Scalepack (Otwinowski & Minor,1997)'
_computing_molecular_graphics    'SHELXTL v6.1 (Sheldrick, 2008)'
_computing_publication_material  'SHELXTL v6.1 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXTL v6.1 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXTL v6.1 (Sheldrick, 2008)'
_diffrn_ambient_temperature      190(2)
_diffrn_detector_area_resol_mean 9
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       'CCD 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  0.0537
_diffrn_reflns_av_sigmaI/netI    0.0245
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -27
_diffrn_reflns_limit_k_max       18
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -7
_diffrn_reflns_number            38562
_diffrn_reflns_theta_full        27.92
_diffrn_reflns_theta_max         27.9
_diffrn_reflns_theta_min         2.9
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.088
_exptl_absorpt_correction_T_max  0.9792
_exptl_absorpt_correction_T_min  0.9723
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'HKL Scalepack (Otwinowski & Minor,1997)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.240
_exptl_crystal_description       block
_exptl_crystal_F_000             744
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.470
_refine_diff_density_min         -0.248
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.075
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     261
_refine_ls_number_reflns         2414
_refine_ls_number_restraints     52
_refine_ls_restrained_S_all      1.074
_refine_ls_R_factor_all          0.0521
_refine_ls_R_factor_gt           0.0465
_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^)+(0.0820P)^2^+0.4167P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1290
_refine_ls_wR_factor_ref         0.1350
_reflns_number_gt                2181
_reflns_number_total             2414
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo1022102_si_002.cif
_cod_data_source_block           wie101z
_cod_database_code               4026015