A case study of the MAC (masked acyl cyanide) oxyhomologation of <i>N</i>,<i>N</i>-dibenzyl-L-phenylalaninal with <i>anti</i> diastereoselectivity: preparation of (2<i>S</i>,3<i>S</i>)-allophenylnorstatin esters.
He, Xuefeng; Buchotte, Marie; Guillot, Régis; Deloisy, Sandrine; Aitken, David J.; Organic & biomolecular chemistry 20 (2022) 1769–1781; doi:10.1039/d1ob02411f

data_7158509
_publ_section_title
;
 A case study of the MAC (masked acyl cyanide) oxyhomologation of
 <i>N</i>,<i>N</i>-dibenzyl-L-phenylalaninal with <i>anti</i>
 diastereoselectivity: preparation of
 (2<i>S</i>,3<i>S</i>)-allophenylnorstatin esters.
;
_journal_issue                   8
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1769
_journal_page_last               1781
_journal_paper_doi               10.1039/d1ob02411f
_journal_volume                  20
_journal_year                    2022
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C41 H45 N O3 Si'
_chemical_formula_sum            'C41 H45 N O3 Si'
_chemical_formula_weight         627.87
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     difmap
_audit_creation_method           SHELXL-2018/3
_audit_update_record
;
2021-06-07 deposited with the CCDC.	2022-02-07 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 107.0600(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.8331(4)
_cell_length_b                   24.5894(10)
_cell_length_c                   13.8643(5)
_cell_measurement_reflns_used    9807
_cell_measurement_temperature    100(1)
_cell_measurement_theta_max      66.84
_cell_measurement_theta_min      3.33
_cell_volume                     3530.7(2)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX3'
_computing_data_reduction        'Bruker SAINT'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXS-97 (Sheldrick 2008)'
_diffrn_ambient_temperature      100(1)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker VENTURE PHOTON100 CMOS'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0379
_diffrn_reflns_av_unetI/netI     0.0297
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       29
_diffrn_reflns_limit_k_min       -29
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            53535
_diffrn_reflns_point_group_measured_fraction_full 0.993
_diffrn_reflns_point_group_measured_fraction_max 0.993
_diffrn_reflns_theta_full        66.836
_diffrn_reflns_theta_max         66.836
_diffrn_reflns_theta_min         3.334
_exptl_absorpt_coefficient_mu    0.880
_exptl_absorpt_correction_T_max  0.9528
_exptl_absorpt_correction_T_min  0.8563
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Bruker APEX3'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.181
_exptl_crystal_description       block
_exptl_crystal_F_000             1344
_exptl_crystal_size_max          0.170
_exptl_crystal_size_mid          0.150
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.477
_refine_diff_density_min         -0.282
_refine_diff_density_rms         0.036
_refine_ls_abs_structure_details
;
 Flack x determined using 5632 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.052(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.024
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     837
_refine_ls_number_reflns         12440
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.024
_refine_ls_R_factor_all          0.0318
_refine_ls_R_factor_gt           0.0308
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0434P)^2^+0.8374P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0787
_refine_ls_wR_factor_ref         0.0793
_reflns_Friedel_coverage         0.941
_reflns_Friedel_fraction_full    0.988
_reflns_Friedel_fraction_max     0.988
_reflns_number_gt                12132
_reflns_number_total             12440
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d1ob02411f2.cif
_cod_data_source_block           RX
_cod_depositor_comments          'Adding full bibliography for 7158509.cif.'
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               7158509
_shelx_estimated_absorpt_t_min   0.869
_shelx_estimated_absorpt_t_max   0.920
_shelx_res_checksum              13681
_shelx_hkl_checksum              53815