A dramatic concentration effect on the stereoselectivity of N-glycosylation for the synthesis of 2'-deoxy-beta-ribonucleosides
Fei Yang; Yugen Zhu; Biao Yu; Chem.Commun. 48 (2012) 7097–; doi:10.1039/c2cc33155a

data_7107964
_publ_section_title
;
 A dramatic concentration effect on the stereoselectivity of
 N-glycosylation for the synthesis of 2'-deoxy-beta-ribonucleosides
;
_journal_name_full               Chem.Commun.
_journal_page_first              7097
_journal_paper_doi               10.1039/c2cc33155a
_journal_volume                  48
_journal_year                    2012
_chemical_absolute_configuration ad
_chemical_formula_sum            'C31 H32 Br N5 O9'
_chemical_formula_weight         698.53
_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   geom
_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            4
_cell_length_a                   5.4310(5)
_cell_length_b                   19.4670(17)
_cell_length_c                   30.338(3)
_cell_measurement_reflns_used    3745
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      47.884
_cell_measurement_theta_min      4.395
_cell_volume                     3207.5(5)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'CCD area detector'
_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     0.71073
_diffrn_reflns_av_R_equivalents  0.0373
_diffrn_reflns_av_sigmaI/netI    0.0642
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       37
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            17333
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         1.70
_exptl_absorpt_coefficient_mu    1.343
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.6311
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.447
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             1440
_exptl_crystal_size_max          0.268
_exptl_crystal_size_mid          0.051
_exptl_crystal_size_min          0.049
_refine_diff_density_max         0.481
_refine_diff_density_min         -0.329
_refine_diff_density_rms         0.052
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.025(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.008
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     424
_refine_ls_number_reflns         6234
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.008
_refine_ls_R_factor_all          0.0705
_refine_ls_R_factor_gt           0.0441
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0447P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0915
_refine_ls_wR_factor_ref         0.1036
_reflns_number_gt                4536
_reflns_number_total             6234
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2cc33155a.txt
_cod_data_source_block           cd211183
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7107964