Catalyst-Controlled Formal [4 + 3] Cycloaddition Applied to the Total Synthesis of (+)-Barekoxide and (-)-Barekol
Yajing Lian; Laura C. Miller; Stephen Born; Richmond Sarpong; Huw M. L. Davies; Journal of the American Chemical Society 132 (2010) 12422–12425; doi:10.1021/ja103916t

data_4103002
_publ_section_title
;
 Catalyst-Controlled Formal [4 + 3] Cycloaddition Applied to the Total
 Synthesis of (+)-Barekoxide and (-)-Barekol
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              12422
_journal_page_last               12425
_journal_paper_doi               10.1021/ja103916t
_journal_volume                  132
_journal_year                    2010
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C20 H34 O'
_chemical_formula_sum            'C20 H34 O'
_chemical_formula_weight         290.47
_space_group_IT_number           1
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                80.027(2)
_cell_angle_beta                 86.454(2)
_cell_angle_gamma                67.354(2)
_cell_formula_units_Z            2
_cell_length_a                   6.0927(2)
_cell_length_b                   7.3057(3)
_cell_length_c                   21.0808(8)
_cell_measurement_reflns_used    4162
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      69.02
_cell_measurement_theta_min      4.26
_cell_volume                     852.89(6)
_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      173(2)
_diffrn_measured_fraction_theta_full 0.841
_diffrn_measured_fraction_theta_max 0.841
_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           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0131
_diffrn_reflns_av_sigmaI/netI    0.0162
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            5328
_diffrn_reflns_theta_full        65.87
_diffrn_reflns_theta_max         65.87
_diffrn_reflns_theta_min         2.13
_exptl_absorpt_coefficient_mu    0.498
_exptl_absorpt_correction_T_max  0.9755
_exptl_absorpt_correction_T_min  0.8609
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.131
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             324
_exptl_crystal_size_max          0.31
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.05
_refine_diff_density_max         0.239
_refine_diff_density_min         -0.232
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.0(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.040
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     379
_refine_ls_number_reflns         3290
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          0.0390
_refine_ls_R_factor_gt           0.0389
_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^)+(0.0815P)^2^+0.1440P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1081
_refine_ls_wR_factor_ref         0.1082
_reflns_number_gt                3277
_reflns_number_total             3290
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja103916t_si_002.cif
_cod_data_source_block           barekols
_cod_database_code               4103002