Versatile strategy to access tricycles related to quassinoids and triterpenes.
Caron, Pierre-Yves; Deslongchamps, Pierre; Organic letters 12 (2010) 508–511; doi:10.1021/ol902711b

data_1503389
_publ_section_title
;
 Versatile strategy to access tricycles related to quassinoids and
 triterpenes.
;
_journal_issue                   3
_journal_name_full               'Organic letters'
_journal_page_first              508
_journal_page_last               511
_journal_paper_doi               10.1021/ol902711b
_journal_volume                  12
_journal_year                    2010
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C25 H32 O4'
_chemical_formula_sum            'C25 H32 O4'
_chemical_formula_weight         396.51
_space_group_IT_number           145
_symmetry_cell_setting           trigonal
_symmetry_Int_Tables_number      145
_symmetry_space_group_name_Hall  'P 32'
_symmetry_space_group_name_H-M   'P 32'
_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                120.00
_cell_formula_units_Z            3
_cell_length_a                   10.1431(10)
_cell_length_b                   10.1431(10)
_cell_length_c                   17.8259(19)
_cell_measurement_reflns_used    6296
_cell_measurement_temperature    173(1)
_cell_measurement_theta_max      27.87
_cell_measurement_theta_min      2.32
_cell_volume                     1588.3(3)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL (Sheldrick, 2008)'
_computing_publication_material  'Bruker SHELXTL (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      173(1)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.963
_diffrn_measurement_device_type  'Bruker AXS SMART1000/P4'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0241
_diffrn_reflns_av_sigmaI/netI    0.0151
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            11070
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         2.32
_diffrn_source                   'fine-focus sealed tube'
_diffrn_source_type              K760
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_T_max  0.9877
_exptl_absorpt_correction_T_min  0.9560
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2004)'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.244
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Irregular
_exptl_crystal_F_000             642
_exptl_crystal_recrystallization_method Ethylacetate/Haxane
_exptl_crystal_size_max          0.55
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.218
_refine_diff_density_min         -0.117
_refine_diff_density_rms         0.030
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.048
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     390
_refine_ls_number_reflns         2337
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0320
_refine_ls_R_factor_gt           0.0289
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0480P)^2^+0.1904P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0738
_refine_ls_wR_factor_ref         0.0779
_reflns_number_gt                2215
_reflns_number_total             2337
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol902711b_si_002.cif
_cod_data_source_block           pd081160
_cod_database_code               1503389