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_4121456
_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_absolute_configuration ad
_chemical_formula_sum            'C29 H35 Br O4'
_chemical_formula_weight         527.48
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXTL
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.5438(6)
_cell_length_b                   10.6784(9)
_cell_length_c                   32.488(3)
_cell_measurement_reflns_used    9945
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      68.33
_cell_measurement_theta_min      2.72
_cell_volume                     2617.1(4)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.987
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  'Helios multilayer optics'
_diffrn_radiation_source         'Bruker MicroStar microfocus rotating anode'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0347
_diffrn_reflns_av_sigmaI/netI    0.0431
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       37
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            14077
_diffrn_reflns_theta_full        66.00
_diffrn_reflns_theta_max         68.32
_diffrn_reflns_theta_min         2.72
_exptl_absorpt_coefficient_mu    2.391
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.733
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.339
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'Rectangular parallelepiped'
_exptl_crystal_F_000             1104
_exptl_crystal_size_max          0.23
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.661
_refine_diff_density_min         -0.510
_refine_diff_density_rms         0.050
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.048(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.028
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     312
_refine_ls_number_reflns         4572
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.028
_refine_ls_R_factor_all          0.0290
_refine_ls_R_factor_gt           0.0283
_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^)+(0.0363P)^2^+0.6807P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0731
_refine_ls_wR_factor_ref         0.0737
_reflns_number_gt                4473
_reflns_number_total             4572
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja413106t_si_001.cif
_cod_data_source_block           v09b
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/crontab/automatic-downloads/current/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               4121456