Versatile Construction of 6-Substituted cis-2,8-Dioxabicyclo[3.3.0]octan-3-ones: Short Enantioselective Total Syntheses of Cheloviolenes A and B and Dendrillolide C.
Slutskyy, Yuriy; Jamison, Christopher R.; Zhao, Peng; Lee, Juyeol; Rhee, Young Ho; Overman, Larry E.; Journal of the American Chemical Society 139 (2017) 7192–7195; doi:10.1021/jacs.7b04265

data_4126189
_publ_section_title
;
 Versatile Construction of 6-Substituted
 cis-2,8-Dioxabicyclo[3.3.0]octan-3-ones: Short Enantioselective Total
 Syntheses of Cheloviolenes A and B and Dendrillolide C.
;
_journal_issue                   21
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              7192
_journal_page_last               7195
_journal_paper_doi               10.1021/jacs.7b04265
_journal_volume                  139
_journal_year                    2017
_chemical_absolute_configuration syn
_chemical_formula_sum            'C20 H30 O4'
_chemical_formula_weight         334.44
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.5876(5)
_cell_length_b                   11.5796(9)
_cell_length_c                   23.9814(19)
_cell_measurement_reflns_used    9890
_cell_measurement_temperature    133(2)
_cell_measurement_theta_max      28.67
_cell_measurement_theta_min      2.45
_cell_volume                     1829.3(2)
_computing_cell_refinement       'Bruker SAINT 8.34a, 2013'
_computing_data_collection       'Bruker APEX2 2014.11-0, 2014'
_computing_data_reduction        'Bruker SAINT 8.34a, 2013'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'Bruker SHELXTL 2014/4'
_diffrn_ambient_temperature      133(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.964
_diffrn_measurement_device_type  'Bruker SMART APEX II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0264
_diffrn_reflns_av_unetI/netI     0.0193
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.964
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            21045
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.936
_diffrn_reflns_theta_full        25.500
_diffrn_reflns_theta_max         28.735
_diffrn_reflns_theta_min         1.698
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_T_max  0.8621
_exptl_absorpt_correction_T_min  0.8261
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker SADABS 2014/5'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.214
_exptl_crystal_density_meas      ?
_exptl_crystal_density_method    not_measured
_exptl_crystal_description       prism
_exptl_crystal_F_000             728
_exptl_crystal_size_max          0.389
_exptl_crystal_size_mid          0.252
_exptl_crystal_size_min          0.215
_refine_diff_density_max         0.263
_refine_diff_density_min         -0.133
_refine_diff_density_rms         0.033
_refine_ls_abs_structure_details
; 
 Flack x determined using 1656 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   -0.1(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.034
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     337
_refine_ls_number_reflns         4421
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.034
_refine_ls_R_factor_all          0.0343
_refine_ls_R_factor_gt           0.0320
_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^)+(0.0541P)^2^+0.1668P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0822
_refine_ls_wR_factor_ref         0.0840
_reflns_Friedel_coverage         0.692
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.900
_reflns_number_gt                4184
_reflns_number_total             4421
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b04265_si_002.cif
_cod_data_source_block           leo294
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_crystal_density_meas' value 'not_measured' was changed to '?'
- the value is perceived as not measured.

Automatic conversion script
Id: cif_fix_values 4973 2017-02-22 13:04:09Z antanas 
;
_cod_database_code               4126189
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.968
_shelx_estimated_absorpt_t_max   0.982
_shelx_res_checksum              99690
_shelx_hkl_checksum              22664