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_1507194
_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 syn
_chemical_formula_moiety         'C21 H28 O4'
_chemical_formula_sum            'C21 H28 O4'
_chemical_formula_weight         344.43
_chemical_name_systematic
; 
(2R,5aR,9aS)-9a-((R)-(3,5-dimethylphenyl)(methoxymethoxy)methyl)-2,6,7,8,9,9a-
hexahydro-1H-2,5a-epoxybenzo[d]oxepine
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 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                 98.78(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   18.037(6)
_cell_length_b                   7.825(5)
_cell_length_c                   13.631(10)
_cell_measurement_reflns_used    2423
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28.700
_cell_measurement_theta_min      0.407
_cell_volume                     1901(2)
_computing_cell_refinement
'DENZO (Otwinowski & Minor, 1997); COLLECT (Nonius B.V., 1999)'
_computing_data_collection
'DENZO (Otwinowski & Minor, 1997); COLLECT (Nonius B.V., 1999)'
_computing_data_reduction        'SCALEPACK (Otwinowski & Minor, 1997)'
_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      293(2)
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_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     0.71070
_diffrn_reflns_av_R_equivalents  0.0251
_diffrn_reflns_av_sigmaI/netI    0.0370
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            10456
_diffrn_reflns_theta_full        28.65
_diffrn_reflns_theta_max         28.65
_diffrn_reflns_theta_min         2.84
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  0.98
_exptl_absorpt_correction_T_min  0.93
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Scalepack (Otwinowski & Minor, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.203
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'elongated thin parallelepiped'
_exptl_crystal_F_000             744
_exptl_crystal_size_max          0.60
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.203
_refine_diff_density_min         -0.148
_refine_diff_density_rms         0.031
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     229
_refine_ls_number_reflns         2606
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0665
_refine_ls_R_factor_gt           0.0440
_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^)+(0.0651P)^2^+0.2645P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1057
_refine_ls_wR_factor_ref         0.1194
_reflns_number_gt                1971
_reflns_number_total             2606
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol300388b_si_003.cif
_cod_data_source_block           compound_2f_C11R
_cod_original_sg_symbol_H-M      C2
_cod_database_code               1507194