Bridgehead enolates and bridgehead alkenes in a welwistatin model series
Boissel, Valerie; Simpkins, Nigel S.; Bhalay, Gurdip; Blake, Alexander J.; Lewis, William; Chemical Communications  (2009) 1398–1400; doi:10.1039/b820674k

data_7111532
_publ_section_title
;
 Bridgehead enolates and bridgehead alkenes in a welwistatin model series
;
_journal_issue                   11
_journal_name_full               'Chemical Communications'
_journal_page_first              1398
_journal_page_last               1400
_journal_paper_doi               10.1039/b820674k
_journal_year                    2009
_chemical_formula_moiety         'C19 H23 N O Si'
_chemical_formula_sum            'C19 H23 N O Si'
_chemical_formula_weight         309.47
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_atom_sites_solution_hydrogens
'Me H atoms from delta-F; others placed geometrically'
_atom_sites_solution_primary     direct
_audit_creation_method           'enCIFer editing of SHELXL97 CIF output'
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   23.565(2)
_cell_length_b                   10.8079(10)
_cell_length_c                   6.5185(6)
_cell_measurement_reflns_used    3122
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      26.9
_cell_measurement_theta_min      2.5
_cell_volume                     1660.2(3)
_computing_cell_refinement       'Bruker SAINT version 6.36A (Bruker, 2002)'
_computing_data_collection       'Bruker SMART version 5.624 (Bruker, 2001)'
_computing_data_reduction        'Bruker SAINT; SHELXTL (Sheldrick, 2008)'
_computing_molecular_graphics    ' ?'
_computing_publication_material
'enCIFer (Allen et al., 2004); PLATON (Spek,2003)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker SMART1000 CCD area detector'
_diffrn_measurement_method       omega
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.039
_diffrn_reflns_av_sigmaI/netI    0.054
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -27
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            10391
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         2.07
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.143
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.238
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       lath
_exptl_crystal_F_000             664
_exptl_crystal_size_max          0.41
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.21
_refine_diff_density_min         -0.20
_refine_diff_density_rms         0.04
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.38(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.93
_refine_ls_hydrogen_treatment    'rigid rotor; riding model'
_refine_ls_matrix_type           full
_refine_ls_number_parameters     204
_refine_ls_number_reflns         3751
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.93
_refine_ls_R_factor_all          0.0502
_refine_ls_R_factor_gt           0.0349
_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^)+(0.034P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0694
_refine_ls_wR_factor_ref         0.0741
_reflns_number_gt                2929
_reflns_number_total             3751
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b820674ksup1.cif
_cod_data_source_block           19
_cod_original_cell_volume        1660.2(4)
_cod_database_code               7111532