Stereoselective generation of vicinal stereogenic quaternary centers by photocycloaddition of 5-methoxy oxazoles to alpha-keto esters: synthesis of erythro beta-hydroxy dimethyl aspartates.
Griesbeck, Axel G.; Bondock, Samir; Lex, Johann; Organic & biomolecular chemistry 2 (2004) 1113–1115; doi:10.1039/b401990c

data_7150371
_publ_section_title
;
 Stereoselective generation of vicinal stereogenic quaternary centers
 by photocycloaddition of 5-methoxy oxazoles to alpha-keto esters:
 synthesis of erythro beta-hydroxy dimethyl aspartates.
;
_journal_issue                   8
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1113
_journal_page_last               1115
_journal_paper_doi               10.1039/b401990c
_journal_volume                  2
_journal_year                    2004
_chemical_formula_sum            'C11 H19 N O6'
_chemical_formula_weight         261.27
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 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                 108.02(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.319(1)
_cell_length_b                   21.573(1)
_cell_length_c                   8.799(1)
_cell_measurement_reflns_used    2722
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.54
_cell_measurement_theta_min      1.89
_cell_volume                     1321.2(3)
_computing_cell_refinement       'Nonius DENZO'
_computing_data_collection       'Nonius COLLECT'
_computing_data_reduction        'Nonius DENZO'
_computing_molecular_graphics    SCHAKAL
_computing_publication_material  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.891
_diffrn_measured_fraction_theta_max 0.891
_diffrn_measurement_device_type  'Nonius KappaCCD'
_diffrn_measurement_method       Phi/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  0.0923
_diffrn_reflns_av_sigmaI/netI    0.1314
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -27
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            5302
_diffrn_reflns_theta_full        27.54
_diffrn_reflns_theta_max         27.54
_diffrn_reflns_theta_min         1.89
_exptl_absorpt_coefficient_mu    0.107
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.314
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             560
_exptl_crystal_size_max          .20
_exptl_crystal_size_mid          .08
_exptl_crystal_size_min          .08
_refine_diff_density_max         0.153
_refine_diff_density_min         -0.232
_refine_diff_density_rms         0.044
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.956
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     218
_refine_ls_number_reflns         2722
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.956
_refine_ls_R_factor_all          0.1965
_refine_ls_R_factor_gt           0.0562
_refine_ls_shift/su_max          0.009
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0535P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1017
_refine_ls_wR_factor_ref         0.1390
_reflns_number_gt                1023
_reflns_number_total             2722
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b401990c.txt
_cod_data_source_block           4b
_cod_original_cell_volume        1321.2(2)
_cod_original_sg_symbol_H-M      P21/c
_cod_database_code               7150371