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_4105371
_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         'C6 H10 O3'
_chemical_formula_sum            'C6 H10 O3'
_chemical_formula_weight         130.14
_chemical_name_systematic
; 
 (S)-3-hydroxy-4,4-dimethyldihydrofuran-2(3H)-one 
;
_space_group_IT_number           145
_symmetry_cell_setting           trigonal
_symmetry_space_group_name_Hall  'P 32'
_symmetry_space_group_name_H-M   'P 32'
_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                120.00
_cell_formula_units_Z            3
_cell_length_a                   9.8337(13)
_cell_length_b                   9.8337(13)
_cell_length_c                   5.9948(7)
_cell_measurement_reflns_used    2000
_cell_measurement_temperature    180(2)
_cell_measurement_theta_max      25
_cell_measurement_theta_min      5
_cell_volume                     502.04(11)
_computing_cell_refinement       'IPDS2.87 (Stoe & Cie, 1997)'
_computing_data_collection       'IPDS2.87 (Stoe & Cie, 1997)'
_computing_data_reduction        'IPDS2.87 (Stoe & Cie, 1997)'
_computing_molecular_graphics    'DIAMOND (Brandenburg, 1999)'
_computing_publication_material  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      180(2)
_diffrn_detector_area_resol_mean 6.667
_diffrn_measured_fraction_theta_full 0.963
_diffrn_measured_fraction_theta_max 0.963
_diffrn_measurement_device       'Stoe IPDS diffractometer'
_diffrn_measurement_method       '\f-oscill.,\f-incr.=1.5\%,133 exposures'
_diffrn_radiation_monochromator  'planar graphite'
_diffrn_radiation_source         'fine-focus sealed X-ray tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0261
_diffrn_reflns_av_sigmaI/netI    0.0323
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       7
_diffrn_reflns_limit_l_min       -6
_diffrn_reflns_number            3481
_diffrn_reflns_theta_full        25.85
_diffrn_reflns_theta_max         25.85
_diffrn_reflns_theta_min         2.39
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.103
_exptl_absorpt_correction_T_max  0.9918
_exptl_absorpt_correction_T_min  0.9502
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.291
_exptl_crystal_density_method    none
_exptl_crystal_description       plate
_exptl_crystal_F_000             210
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.127
_refine_diff_density_min         -0.097
_refine_diff_density_rms         0.025
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.7(9)
_refine_ls_extinction_coef       0.047(8)
_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   0.967
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_parameters     123
_refine_ls_number_reflns         1221
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.966
_refine_ls_R_factor_all          0.0319
_refine_ls_R_factor_gt           0.0256
_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^)+(0.0260P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0469
_refine_ls_wR_factor_ref         0.0479
_reflns_number_gt                1069
_reflns_number_total             1221
_reflns_threshold_expression     I>2sigma(I)
_cod_data_source_file            ja907054y_si_004.cif
_cod_data_source_block           ent-7
_cod_original_sg_symbol_H-M      'P 3 2'
_cod_database_code               4105371