Enantioselective synthesis of furo[2,3-b]furans, a spongiane diterpenoid substructure.
Weisser, Roland; Yue, Weimin; Reiser, Oliver; Organic letters 7 (2005) 5353–5356; doi:10.1021/ol051457m

data_1556112
_publ_section_title
;
 Enantioselective synthesis of furo[2,3-b]furans, a spongiane diterpenoid
 substructure.
;
_journal_issue                   24
_journal_name_full               'Organic letters'
_journal_page_first              5353
_journal_page_last               5356
_journal_paper_doi               10.1021/ol051457m
_journal_volume                  7
_journal_year                    2005
_chemical_absolute_configuration unk
_chemical_compound_source        'see text'
_chemical_formula_moiety         'C20 H20 O5'
_chemical_formula_structural     'C20 H20 O5'
_chemical_formula_sum            'C20 H20 O5'
_chemical_formula_weight         340.36
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_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
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.7104(5)
_cell_length_b                   14.5249(16)
_cell_length_c                   20.567(2)
_cell_measurement_reflns_used    4437
_cell_measurement_temperature    173
_cell_measurement_theta_max      25.95
_cell_measurement_theta_min      1.98
_cell_volume                     1705.9(3)
_computing_cell_refinement       'STOE (1998)'
_computing_data_collection       'STOE (1998)'
_computing_data_reduction        'STOE (1998)'
_computing_molecular_graphics    'PLATON (Spek, 1990)'
_computing_publication_material  'PLATON (Spek, 1990)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR-97 (Altomare, 1993)'
_diffrn_ambient_temperature      173(1)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'STOE-IPDS diffractometer'
_diffrn_measurement_method       rotation
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0991
_diffrn_reflns_av_sigmaI/netI    0.1318
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            13119
_diffrn_reflns_reduction_process ' ?'
_diffrn_reflns_theta_full        25.95
_diffrn_reflns_theta_max         25.95
_diffrn_reflns_theta_min         1.98
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_T_max  0.998
_exptl_absorpt_correction_T_min  0.970
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.325
_exptl_crystal_density_method    'Not Measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             720
_exptl_crystal_size_max          0.320
_exptl_crystal_size_mid          0.040
_exptl_crystal_size_min          0.020
_refine_diff_density_max         0.210
_refine_diff_density_min         -0.131
_refine_diff_density_rms         0.040
_refine_ls_abs_structure_details 'Flack H.D. (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.3(17)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.694
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     226
_refine_ls_number_reflns         3288
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.694
_refine_ls_R_factor_all          0.0913
_refine_ls_R_factor_gt           0.0392
_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^)+(0.0213P)^2^]         where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0711
_refine_ls_wR_factor_ref         0.0817
_reflns_number_gt                1690
_reflns_number_total             3288
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ol051457mrom20050622_061735.cif
_cod_data_source_block           d213
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_symmetry_cell_setting' value 'Orthorhombic' was changed
to 'orthorhombic' in accordance with the
/home/saulius/struct/COD-crude-data/automatic-downloads/DataCite-retrospective/ACS/depositions/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 last updated on
2011-04-26.

Automatic conversion script
Id: cif_fix_values 6909 2019-04-08 15:41:33Z antanas 
;
_cod_database_code               1556112