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_1507192
_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_absolute_configuration ad
_chemical_formula_moiety         'C21 H28 O6'
_chemical_formula_sum            'C21 H28 O6'
_chemical_formula_weight         376.43
_chemical_name_systematic
; 
 rac-[(2R,5aR,9aS)-9a-((R)]-(3,5-dimethoxyphenyl)(methoxymethoxy)
methyl)-2,6,7,8,9,9a-hexahydro-1H-2,5a-epoxybenzo[d]oxepine 
;
_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   difmap
_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            8
_cell_length_a                   13.3486(6)
_cell_length_b                   14.6574(6)
_cell_length_c                   20.1067(14)
_cell_measurement_reflns_used    993
_cell_measurement_temperature    185(2)
_cell_measurement_theta_max      67.5
_cell_measurement_theta_min      13.4
_cell_volume                     3934.0(4)
_computing_cell_refinement       'CrystalClear-SM Expert 2.0 r4 (Rigaku, 2009)'
_computing_data_collection       'CrystalClear-SM Expert 2.0 r4 (Rigaku, 2009)'
_computing_data_reduction        'CrystalClear-SM Expert 2.0 r4 (Rigaku, 2009)'
_computing_molecular_graphics    'PLATON (Spek, 2003)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement
'SHELXL97 (Sheldrick, 2008); CRYSTALBUILDER (Welter, 2006)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      185(2)
_diffrn_detector_type
'RAPID II large area curved imaging plate detector '
_diffrn_measured_fraction_theta_full 0.985
_diffrn_measured_fraction_theta_max 0.985
_diffrn_measurement_device_type  'Rigaku rapid II RAXIS conversion'
_diffrn_measurement_method       'profile data from \w-scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54187
_diffrn_reflns_av_R_equivalents  0.0356
_diffrn_reflns_av_sigmaI/netI    0.0328
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       17
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            22963
_diffrn_reflns_theta_full        68.24
_diffrn_reflns_theta_max         68.24
_diffrn_reflns_theta_min         6.63
_exptl_absorpt_coefficient_mu    0.759
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.761
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'FS_ABSCOR (Rigaku, 2009)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.271
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'parallelepipedic block'
_exptl_crystal_F_000             1616
_exptl_crystal_size_max          0.58
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.24
_refine_diff_density_max         0.130
_refine_diff_density_min         -0.189
_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   0.07(16)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.108
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     493
_refine_ls_number_reflns         6779
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.108
_refine_ls_R_factor_all          0.0477
_refine_ls_R_factor_gt           0.0390
_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^)+(0.0539P)^2^+0.4247P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0952
_refine_ls_wR_factor_ref         0.1118
_reflns_number_gt                5679
_reflns_number_total             6779
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol300388b_si_003.cif
_cod_data_source_block           compound_2c_C11R
_cod_database_code               1507192