Diverging Pathways to Topologically Complex Polycyclic Bis-acetals and Their Ring System Interchange.
Castillo, Rafael R.; Aquino, Maurizio; Gandara, Zoila; Safir, Imad; Elkhayat, Zobida; Retailleau, Pascal; Arseniyadis, Siméon; Organic letters 14 (2012) 1628–1631; doi:10.1021/ol300388b

data_1507198
_publ_section_title
;
 Diverging Pathways to Topologically Complex Polycyclic Bis-acetals and
 Their Ring System Interchange.
;
_journal_issue                   6
_journal_name_full               'Organic letters'
_journal_page_first              1628
_journal_page_last               1631
_journal_paper_doi               10.1021/ol300388b
_journal_volume                  14
_journal_year                    2012
_chemical_formula_moiety         '0.81 (C22 H28 O8), 0.19 (C22 H28 O9, H2 O)'
_chemical_formula_sum            'C22 H28.38 O8.38'
_chemical_formula_weight         426.78
_chemical_name_systematic
; 
 mixture of rac (2S,4S,4aR,6R,6aS,10aS)-6-(3,4,5-trimethoxyphenyl)
hexahydro-4H-2,6a-methano[1,3] dioxino[5,4-c]isobenzofuran-4-yl
acetate 
and of rac (2S,4S,4aR,6R,6aR,10aS)-6-hydroxy-6-(3,4,5-trimethoxyphenyl)
hexahydro-4H-2,6a-methano[1,3]dioxino[5,4-c]isobenzofuran-4-yl acetate
hydrate  0.81:0.19
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   difmap
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 94.281(8)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.611(3)
_cell_length_b                   8.440(2)
_cell_length_c                   23.181(5)
_cell_measurement_reflns_used    3995
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25.350
_cell_measurement_theta_min      0.998
_cell_volume                     2070.2(9)
_computing_cell_refinement
'DENZO (Otwinowski & Minor, 1997) COLLECT (Hooft, 1998)'
_computing_data_collection
'DENZO (Otwinowski & Minor, 1997) COLLECT (Hooft, 1998)'
_computing_data_reduction        'HKL package (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'PLATON (Spek, 1980-2004)'
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR-97 (Altomare et al, 1999)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Nonius kappa-CCD diffractometer'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0226
_diffrn_reflns_av_sigmaI/netI    0.0331
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            20645
_diffrn_reflns_theta_full        25.36
_diffrn_reflns_theta_max         25.36
_diffrn_reflns_theta_min         2.51
_exptl_absorpt_coefficient_mu    0.105
_exptl_absorpt_correction_T_max  0.976
_exptl_absorpt_correction_T_min  0.855
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Scalepack (Otwinowski & Minor, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.369
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'regular block'
_exptl_crystal_F_000             909
_exptl_crystal_size_max          0.52
_exptl_crystal_size_mid          0.36
_exptl_crystal_size_min          0.23
_refine_diff_density_max         0.179
_refine_diff_density_min         -0.174
_refine_diff_density_rms         0.034
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.038
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     289
_refine_ls_number_reflns         3775
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.038
_refine_ls_R_factor_all          0.0705
_refine_ls_R_factor_gt           0.0447
_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^)+(0.0465P)^2^+0.7310P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1017
_refine_ls_wR_factor_ref         0.1144
_reflns_number_gt                2680
_reflns_number_total             3775
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol300388b_si_003.cif
_cod_data_source_block           compound_4d
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               1507198