Investigation of a route to ibotenic acid analogues via a reduced pyroglutamate template.
Ahmed, Omar; Hitchcock, Peter B.; Young, Douglas W.; Organic & biomolecular chemistry 4 (2006) 1596–1603; doi:10.1039/b600195e

data_7150438
_publ_section_title
;
 Investigation of a route to ibotenic acid analogues via a reduced
 pyroglutamate template.
;
_journal_issue                   8
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1596
_journal_page_last               1603
_journal_paper_doi               10.1039/b600195e
_journal_volume                  4
_journal_year                    2006
_chemical_absolute_configuration syn
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         'C28 H39 N O6 Si'
_chemical_formula_structural     'C28 H39 N O6 Si'
_chemical_formula_sum            'C28 H39 N O6 Si'
_chemical_formula_weight         513.69
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      4
_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_conform_dict_location     ftp://ftp.iucr.org/cifdics/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.1
_audit_creation_date             2000-10-27T14:56:38-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 102.434(3)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   7.6412(4)
_cell_length_b                   11.8424(9)
_cell_length_c                   15.8245(7)
_cell_measurement_reflns_used    4220
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      25.028
_cell_measurement_theta_min      3.705
_cell_measurement_wavelength     0.71073
_cell_volume                     1398.37(14)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_reduction
'HKL Denzo and Scalepack (Otwinowski & Minor 1997)'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device       KappaCCD
_diffrn_measurement_method       CCD
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0442
_diffrn_reflns_av_unetI/netI     0.0637
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            6757
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         3.78
_exptl_absorpt_coefficient_mu    0.125
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.22
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             552
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.3
_exptl_crystal_size_min          0.1
_refine_diff_density_max         0.175
_refine_diff_density_min         -0.22
_refine_diff_density_rms         0.042
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.11(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.032
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     337
_refine_ls_number_reflns         3805
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.032
_refine_ls_R_factor_all          0.0509
_refine_ls_R_factor_gt           0.0417
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0308P)^2^+0.3855P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0889
_refine_ls_wR_factor_ref         0.0945
_reflns_number_gt                3372
_reflns_number_total             3805
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b600195e.txt
_cod_data_source_block           oct3700
_cod_original_sg_symbol_H-M      P2(1)
_cod_database_code               7150438