Cyclopropene cycloadditions with annulated furans: total synthesis of (+)- and (-)-frondosin B and (+)-frondosin a.
Oblak, E. Zachary; Vanheyst, Michael D.; Li, Jin; Wiemer, Andrew J.; Wright, Dennis L.; Journal of the American Chemical Society 136 (2014) 4309–4315; doi:10.1021/ja413106t

data_4121458
_publ_section_title
;
 Cyclopropene cycloadditions with annulated furans: total synthesis of
 (+)- and (-)-frondosin B and (+)-frondosin a.
;
_journal_issue                   11
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              4309
_journal_page_last               4315
_journal_paper_doi               10.1021/ja413106t
_journal_volume                  136
_journal_year                    2014
_chemical_formula_moiety         'Si O4 C25 H34'
_chemical_formula_sum            'C25 H34 O4 Si'
_chemical_formula_weight         426.63
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_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
_cell_angle_alpha                100.102(7)
_cell_angle_beta                 104.084(7)
_cell_angle_gamma                109.826(8)
_cell_formula_units_Z            2
_cell_length_a                   9.68701(18)
_cell_length_b                   10.1076(2)
_cell_length_c                   13.6310(10)
_cell_measurement_reflns_used    9574
_cell_measurement_temperature    93
_cell_measurement_theta_max      68.26
_cell_measurement_theta_min      3.48
_cell_volume                     1168.12(14)
_computing_cell_refinement       'CrystalClear-SM Expert 2.0 r5'
_computing_data_collection       'CrystalClear-SM Expert 2.0 r5 (Rigaku, 2010)'
_computing_data_reduction        'CrystalClear-SM Expert 2.0 r5'
_computing_molecular_graphics    'CrystalStructure 4.0'
_computing_publication_material  'CrystalStructure 4.0 (Rigaku, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR2004 (Burla, et al., 2005)'
_diffrn_ambient_temperature      93
_diffrn_detector_area_resol_mean 10.000
_diffrn_measured_fraction_theta_full 0.967
_diffrn_measured_fraction_theta_max 0.967
_diffrn_measurement_device_type  'Rigaku R-AXIS RAPID imaging plate'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54187
_diffrn_reflns_av_R_equivalents  0.0346
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            11849
_diffrn_reflns_theta_full        68.22
_diffrn_reflns_theta_max         68.22
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.107
_exptl_absorpt_correction_T_max  0.876
_exptl_absorpt_correction_T_min  0.759
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
    Higashi, T. (1995). Program for Absorption Correction.
    Rigaku Corporation, Tokyo, Japan.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.213
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             460.00
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.580
_refine_diff_density_min         -0.340
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.090
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     271
_refine_ls_number_reflns         4134
_refine_ls_number_restraints     0
_refine_ls_R_factor_gt           0.0404
_refine_ls_shift/su_max          0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0313P)^2^+0.9568P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1103
_reflns_number_gt                3067
_reflns_number_total             4134
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            ja413106t_si_003.cif
_cod_data_source_block           '_ZO01'
_cod_original_formula_sum        'Si O4 C25 H34'
_cod_database_code               4121458