Cation Clock Permits Distinction Between the Mechanisms of α- and β-O- and β-C-Glycosylation in the Mannopyranose Series: Evidence for the Existence of a Mannopyranosyl Oxocarbenium Ion
Min Huang; Pascal Retailleau; Luis Bohé; David Crich; Journal of the American Chemical Society 134 (2012) 14746–14749; doi:10.1021/ja307266n

data_4118607
_publ_contact_author_address
;
Department of Chemistry, Wayne State University 35
Detroit, MI 48202
USA.
;
_publ_contact_author_email       Dcrich@chem.wayne.edu
_publ_contact_author_fax         '(01) 313 577 8822'
_publ_contact_author_name        'CRICH, David'
_publ_contact_author_phone       '(01) 313 577 7784'
_publ_section_title
;
 Cation Clock Permits Distinction Between the Mechanisms of \a- and \b-O-
 and \b-C-Glycosylation in the Mannopyranose Series: Evidence for the
 Existence of a Mannopyranosyl Oxocarbenium Ion
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              14746
_journal_page_last               14749
_journal_paper_doi               10.1021/ja307266n
_journal_volume                  134
_journal_year                    2012
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C24 H26 O5'
_chemical_formula_sum            'C24 H26 O5'
_chemical_formula_weight         394.45
_chemical_name_systematic
; 
 (2R,4aR,5aR,9aS,10S,10aR)-10-(benzyloxy)-7-methylene-2-phenyloctahydro
 -4H-pyrano[2',3':5,6]pyrano[3,2-d][1,3]dioxine 
;
_space_group_IT_number           18
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2 2ab'
_symmetry_space_group_name_H-M   'P 21 21 2'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   15.406(3)
_cell_length_b                   28.983(5)
_cell_length_c                   4.5886(9)
_cell_measurement_reflns_used    456
_cell_measurement_temperature    193(2)
_cell_measurement_theta_max      49.4
_cell_measurement_theta_min      9.2
_cell_volume                     2048.9(7)
_computing_cell_refinement       'CrystalClear-SM Expert 2.0 r4 (Rigaku, 2009)'
_computing_data_collection       'CrystalClear-SM Expert 2.0 r4 (Rigaku, 2009)'
_computing_data_reduction        'CrystalClear-SM Expert 2.0 r4 (Rigaku, 2009)'
_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      193(2)
_diffrn_detector_type
'RAPID II large area curved imaging plate detector '
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Rigaku rapid II RAXIS conversion'
_diffrn_measurement_method       'profile data from \w-scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54187
_diffrn_reflns_av_R_equivalents  0.1323
_diffrn_reflns_av_sigmaI/netI    0.1525
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       -28
_diffrn_reflns_limit_l_max       3
_diffrn_reflns_limit_l_min       -4
_diffrn_reflns_number            8238
_diffrn_reflns_theta_full        49.99
_diffrn_reflns_theta_max         49.99
_diffrn_reflns_theta_min         6.51
_exptl_absorpt_coefficient_mu    0.721
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.420
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'FS_ABSCOR (Rigaku, 2009)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.279
_exptl_crystal_description       'elongated fiber'
_exptl_crystal_F_000             840
_exptl_crystal_size_max          0.56
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.231
_refine_diff_density_min         -0.216
_refine_diff_density_rms         0.049
_refine_ls_abs_structure_details
'Flack H D (1983), Acta Cryst. A39, 876-881; 816 Friedel pairs'
_refine_ls_abs_structure_Flack   -0.2(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.999
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     262
_refine_ls_number_reflns         2107
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.999
_refine_ls_R_factor_all          0.1072
_refine_ls_R_factor_gt           0.0741
_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^)+(0.0740P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1442
_refine_ls_wR_factor_ref         0.1735
_reflns_number_gt                1352
_reflns_number_total             2107
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja307266n_si_002_2.cif
_cod_data_source_block           Hum2-017-F28
_cod_database_code               4118607