Asymmetric Histidine-Catalyzed Cross-Aldol Reactions of Enolizable Aldehydes: Access to Defined Configured Quaternary Stereogenic Centers
Morris Markert; Ulf Scheffler; Rainer Mahrwald; Journal of the American Chemical Society 131 (2009) 16642–16643; doi:10.1021/ja907054y

data_4105372
_publ_section_title
;
 Asymmetric Histidine-Catalyzed Cross-Aldol Reactions of Enolizable
 Aldehydes: Access to Defined Configured Quaternary Stereogenic Centers
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              16642
_journal_page_last               16643
_journal_paper_doi               10.1021/ja907054y
_journal_volume                  131
_journal_year                    2009
_chemical_absolute_configuration rm
_chemical_formula_moiety         'C12 H22 O6'
_chemical_formula_sum            'C12 H22 O6'
_chemical_formula_weight         262.30
_chemical_name_systematic
; 
 (S)-((R)-2,2-dimethyl-1,3-dioxalan-4-yl)((S)-4-(hydroxymethyl)2,2-
dimethyl-1,3-dioxolan-4-yl)methanol 
;
_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                 93.479(14)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.0425(13)
_cell_length_b                   6.6274(8)
_cell_length_c                   25.446(5)
_cell_measurement_reflns_used    2000
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      25
_cell_measurement_theta_min      5
_cell_volume                     1353.8(4)
_computing_cell_refinement       'X-AREA (Stoe & Cie, 2002)'
_computing_data_collection       'X-AREA (Stoe & Cie, 2002)'
_computing_data_reduction        'X-RED (Stoe & Cie, 2002)'
_computing_molecular_graphics    'DIAMOND (Brandenburg & Berndt, 1999)'
_computing_publication_material  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR2004 (Burla et al., 2005)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 6.67
_diffrn_measured_fraction_theta_full 0.880
_diffrn_measured_fraction_theta_max 0.880
_diffrn_measurement_device       'Stoe IPDS-2t diffractometer'
_diffrn_measurement_method       '\w-rotation,\w-incr.=1\%,266 exposures'
_diffrn_radiation_collimation    '0.5 mm diameter monocapillary'
_diffrn_radiation_monochromator  'planar graphite'
_diffrn_radiation_source         'long fine focus sealed X-ray tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1849
_diffrn_reflns_av_sigmaI/netI    0.1042
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            20740
_diffrn_reflns_theta_full        25.98
_diffrn_reflns_theta_max         25.98
_diffrn_reflns_theta_min         2.41
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.102
_exptl_absorpt_correction_T_max  0.9939
_exptl_absorpt_correction_T_min  0.9506
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.287
_exptl_crystal_density_method    none
_exptl_crystal_description       needle
_exptl_crystal_F_000             568
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.646
_refine_diff_density_min         -0.345
_refine_diff_density_rms         0.110
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.8(16)
_refine_ls_extinction_coef       0.005(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.993
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     338
_refine_ls_number_reflns         4172
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.993
_refine_ls_R_factor_all          0.1142
_refine_ls_R_factor_gt           0.0883
_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^)+(0.1566P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2102
_refine_ls_wR_factor_ref         0.2329
_reflns_number_gt                2879
_reflns_number_total             4172
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            ja907054y_si_005.cif
_cod_data_source_block           reduced_hemiacetal_8
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4105372