Asymmetric Synthesis of α,α-Disubstituted Amino Acids by Cycloaddition of (E)-Ketonitrones with Vinyl Ethers.
Zhang, Xiaofei; Cividino, Pascale; Poisson, Jean-François; Shpak-Kraievskyi, Pavlo; Laurent, Mathieu Y; Martel, Arnaud; Dujardin, Gilles; Py, Sandrine; Organic letters 16 (2014) 1936–1939; doi:10.1021/ol500483t

data_1514213
_publ_section_title
;
 Asymmetric Synthesis of \a,\a-Disubstituted Amino Acids by Cycloaddition
 of (E)-Ketonitrones with Vinyl Ethers.
;
_journal_issue                   7
_journal_name_full               'Organic letters'
_journal_page_first              1936
_journal_page_last               1939
_journal_paper_doi               10.1021/ol500483t
_journal_volume                  16
_journal_year                    2014
_chemical_absolute_configuration rm
_chemical_formula_moiety         'C28 H44 N O11'
_chemical_formula_sum            'C28 H44 N O11'
_chemical_formula_weight         570.64
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C 2y'
_symmetry_space_group_name_H-M   'C 1 2 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                 112.536(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   26.5845(9)
_cell_length_b                   9.3012(3)
_cell_length_c                   14.1691(4)
_cell_measurement_reflns_used    9125
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      49.751
_cell_measurement_theta_min      4.685
_cell_volume                     3236.03(18)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_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  0.0666
_diffrn_reflns_av_sigmaI/netI    0.0474
_diffrn_reflns_limit_h_max       35
_diffrn_reflns_limit_h_min       -35
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            61030
_diffrn_reflns_theta_full        28.38
_diffrn_reflns_theta_max         28.38
_diffrn_reflns_theta_min         1.56
_exptl_absorpt_coefficient_mu    0.090
_exptl_absorpt_correction_T_max  0.997
_exptl_absorpt_correction_T_min  0.983
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SHELX76; Sheldrick, 2008)'
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.171
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1228
_exptl_crystal_size_max          0.739
_exptl_crystal_size_mid          0.155
_exptl_crystal_size_min          0.037
_refine_diff_density_max         0.428
_refine_diff_density_min         -0.509
_refine_diff_density_rms         0.170
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.3(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.069
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     368
_refine_ls_number_reflns         8062
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.069
_refine_ls_R_factor_all          0.0980
_refine_ls_R_factor_gt           0.0541
_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^)+(0.1011P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1463
_refine_ls_wR_factor_ref         0.1799
_reflns_number_gt                5106
_reflns_number_total             8062
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol500483t_si_002.cif
_cod_data_source_block           c28h44no11
_cod_depositor_comments
;Adding full bibliography for
 ./tmp-cod-update-bibliographies-8800/cifs/1514213.cif.
;
_cod_original_cell_volume        3236.02(18)
_cod_original_sg_symbol_H-M      'C 2'
_cod_database_code               1514213