Conformational effects in diastereoselective aryne Diels-Alder reactions: synthesis of benzo-fused [2.2.1] heterobicycles.
Webster, Robert; Lautens, Mark; Organic letters 11 (2009) 4688–4691; doi:10.1021/ol9019869

data_1504227
_publ_section_title
;
 Conformational effects in diastereoselective aryne Diels-Alder reactions:
 synthesis of benzo-fused [2.2.1] heterobicycles.
;
_journal_issue                   20
_journal_name_full               'Organic letters'
_journal_page_first              4688
_journal_page_last               4691
_journal_paper_doi               10.1021/ol9019869
_journal_volume                  11
_journal_year                    2009
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C18 H26 O2 Si'
_chemical_formula_sum            'C18 H26 O2 Si'
_chemical_formula_weight         302.48
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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                 97.689(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   5.9876(5)
_cell_length_b                   7.3491(3)
_cell_length_c                   19.9858(18)
_cell_measurement_reflns_used    5697
_cell_measurement_temperature    150(1)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3.1
_cell_volume                     871.54(11)
_computing_cell_refinement       'Denzo-SMN (Otwinowski & Minor, 1997)'
_computing_data_collection       'Collect (Nonius B.V., 1997-2002)'
_computing_data_reduction        Denzo-SMN
_computing_molecular_graphics    'PLATON (Spek, 2003)'
_computing_publication_material  'SHELXTL V6.1'
_computing_structure_refinement  'SHELXTL V6.1 (Sheldrick, 2008)'
_computing_structure_solution    'SIR-92 (Altomare et al., 1994)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 9
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.974
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       '\f scans and \w scans with \k offsets'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0592
_diffrn_reflns_av_sigmaI/netI    0.0762
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            5697
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         3.09
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.137
_exptl_absorpt_correction_T_max  0.992
_exptl_absorpt_correction_T_min  0.788
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
multi-scan from symmetry-related measurements 
Sortav (Blessing 1995)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.153
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             328
_exptl_crystal_size_max          0.20
_exptl_crystal_size_mid          0.15
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.378
_refine_diff_density_min         -0.265
_refine_diff_density_rms         0.053
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.13(17)
_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     196
_refine_ls_number_reflns         3612
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.038
_refine_ls_R_factor_all          0.0724
_refine_ls_R_factor_gt           0.0555
_refine_ls_shift/su_max          0.016
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0597P)^2^+0.2455P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1285
_refine_ls_wR_factor_ref         0.1405
_reflns_number_gt                2986
_reflns_number_total             3612
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ol9019869_si_006.cif
_cod_data_source_block           k08220
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               1504227