C2-Symmetric Enantiopure Ethanotethered Bis(α,β-butenolides) as Templates for Asymmetric Synthesis. Application to the Synthesis of (+)-Grandisol
Pedro de March; Marta Figueredo; Josep Font; Javier Raya; Ángel Álvarez-Larena; Juan F. Piniella; Journal of Organic Chemistry 68 (2003) 2437–2447; doi:10.1021/jo026705w

data_4022331
_publ_section_title
;
 C2-Symmetric Enantiopure Ethanotethered Bis(\a,\b-butenolides)
 as Templates for Asymmetric Synthesis.
 Application to the Synthesis of (+)-Grandisol
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              2437
_journal_page_last               2447
_journal_paper_doi               10.1021/jo026705w
_journal_volume                  68
_journal_year                    2003
_chemical_formula_sum            'C16 H26 O6 Si2'
_chemical_formula_weight         370.55
_chemical_name_systematic
; 
(3aR,4R,5S,6R,6aS)-5,6-bis(trimethylsilyloxy)-3a,5,6,6a-tetrahydrospiro 
[cyclopenta[b]furo-4(5H),2'(5'H)-furan]-2(3H),5'-dione 
;
_space_group_IT_number           19
_symmetry_cell_setting           monoclinic
_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           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.483(2)
_cell_length_b                   11.221(3)
_cell_length_c                   25.339(5)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      13.96
_cell_measurement_theta_min      9.90
_cell_volume                     2127.6(9)
_computing_cell_refinement       'CAD4 (Enraf-Nonius)'
_computing_data_collection       'CAD4 (Enraf-Nonius)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.862
_diffrn_measured_fraction_theta_max 0.862
_diffrn_measurement_device_type  'Enraf-Nonius CAD4'
_diffrn_measurement_method       'omega/2theta scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0633
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            1860
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         1.61
_diffrn_standards_decay_%        61.1
_diffrn_standards_interval_time  120
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.191
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  1.000
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.157
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    .
_exptl_crystal_description       prism
_exptl_crystal_F_000             792
_exptl_crystals_number           4
_refine_diff_density_max         0.396
_refine_diff_density_min         -0.397
_refine_diff_density_rms         0.073
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.4(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.131
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         1860
_refine_ls_number_restraints     8
_refine_ls_restrained_S_all      1.130
_refine_ls_R_factor_all          0.1200
_refine_ls_R_factor_gt           0.1037
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0945P)^2^+5.5077P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2433
_refine_ls_wR_factor_ref         0.2496
_reflns_number_gt                1529
_reflns_number_total             1860
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo026705wsi20030115_035834_2.cif
_cod_data_source_block           compoundI
_cod_depositor_comments
;
The following automatic conversions were performed:

'_refine_ls_weighting_scheme' value 'calc
w=1/[\s^2^(Fo^2^)+(0.0945P)^2^+5.5077P] where P=(Fo^2^+2Fc^2^)/3' was
changed to 'calc'. New tag '_refine_ls_weighting_details' was
created. The value of the new tag was set to
'w=1/[\s^2^(Fo^2^)+(0.0945P)^2^+5.5077P] where P=(Fo^2^+2Fc^2^)/3'.

Automatic conversion script
Id: cif_fix_values 3143 2015-03-26 13:38:13Z robertas 
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_cod_database_code               4022331