cis-Dihydroxylated α-Trifluoromethylated N,O-Acetal from l-Tartaric Acid: Synthesis of Tetrasubstituted Stereocenter via Diastereoselective Pictet-Spengler Cyclization of N-Acyliminium Ions
Ben Jamaa, Abdelkhalek; Latrache, Mohammed; Riguet, Emmanuel; Grellepois, Fabienne; The Journal of Organic Chemistry  (2020) –; doi:10.1021/acs.joc.0c00801

data_4038609
_publ_section_title
;
 cis-Dihydroxylated \a-Trifluoromethylated N,O-Acetal from l-Tartaric
 Acid: Synthesis of Tetrasubstituted Stereocenter via Diastereoselective
 Pictet-Spengler Cyclization of N-Acyliminium Ions
;
_journal_name_full               'The Journal of Organic Chemistry'
_journal_paper_doi               10.1021/acs.joc.0c00801
_journal_year                    2020
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C18 H20 F3 N O5'
_chemical_formula_sum            'C18 H20 F3 N O5'
_chemical_formula_weight         387.35
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2019-05-16
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.6589(2)
_cell_length_b                   9.9867(2)
_cell_length_c                   20.1991(5)
_cell_measurement_reflns_used    9820
_cell_measurement_temperature    102(2)
_cell_measurement_theta_max      72.45
_cell_measurement_theta_min      4.38
_cell_volume                     1746.69(7)
_computing_cell_refinement       'SAINT V8.38A (?, 2016)'
_computing_data_reduction        'SAINT V8.38A (?, 2016)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL (Sheldrick, 2008)'
_computing_structure_solution    'XT (Sheldrick, 2015)'
_diffrn_ambient_temperature      102
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0385
_diffrn_reflns_av_unetI/netI     0.0256
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       24
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            18367
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.995
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         72.450
_diffrn_reflns_theta_min         4.378
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.103
_exptl_absorpt_correction_T_max  0.7536
_exptl_absorpt_correction_T_min  0.6546
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'SADABS-2016/2 (Bruker,2016/2) was used for absorption correction. wR2(int) was 0.0970 before and 0.0667 after correction. The Ratio of minimum to maximum transmission is 0.8686. The \l/2 correction factor is Not present.'
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.473
_exptl_crystal_description       prism
_exptl_crystal_F_000             808
_exptl_crystal_size_max          0.492
_exptl_crystal_size_mid          0.351
_exptl_crystal_size_min          0.188
_refine_diff_density_max         0.233
_refine_diff_density_min         -0.158
_refine_diff_density_rms         0.039
_refine_ls_abs_structure_details
;
 Flack x determined using 1348 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.01(5)
_refine_ls_extinction_coef       0.0015(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2017/1 (Sheldrick 2017)'
_refine_ls_goodness_of_fit_ref   1.082
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     249
_refine_ls_number_reflns         3443
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.082
_refine_ls_R_factor_all          0.0302
_refine_ls_R_factor_gt           0.0284
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0219P)^2^+0.5866P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0631
_refine_ls_wR_factor_ref         0.0641
_reflns_Friedel_coverage         0.727
_reflns_Friedel_fraction_full    0.992
_reflns_Friedel_fraction_max     0.989
_reflns_number_gt                3309
_reflns_number_total             3443
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo0c00801_si_002.cif
_cod_data_source_block           19fg043_0m_a
_cod_database_code               4038609
_shelx_shelxl_version_number     2017/1
_shelx_estimated_absorpt_t_max   0.819
_shelx_estimated_absorpt_t_min   0.613
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2.a Ternary CH refined with riding coordinates:
 C13(H13), C14(H14)
2.b Secondary CH2 refined with riding coordinates:
 C9(H9A,H9B), C10(H10A,H10B)
2.c Aromatic/amide H refined with riding coordinates:
 C5(H5), C8(H8)
2.d Idealised Me refined as rotating group:
 C1(H1A,H1B,H1C), C2(H2A,H2B,H2C), C17(H17A,H17B,H17C), C18(H18A,H18B,H18C)
;
_shelx_res_checksum              441
_shelx_hkl_checksum              38919
_olex2_submission_special_instructions 'No special instructions were received'