Brønsted Acid-Catalyzed Epimerization-Free Preparation of Dual-Protected Amino Acid Derivatives.
de Castro, Pedro P.; Rimulo, Isabela M. R.; de Almeida, Angelina M.; Diniz, Renata; Amarante, Giovanni W.; ACS omega 2 (2017) 2967–2976; doi:10.1021/acsomega.7b00523

data_4516880
_publ_section_title
;
 Br\/onsted Acid-Catalyzed Epimerization-Free Preparation of
 Dual-Protected Amino Acid Derivatives.
;
_journal_issue                   6
_journal_name_full               'ACS omega'
_journal_page_first              2967
_journal_page_last               2976
_journal_paper_doi               10.1021/acsomega.7b00523
_journal_volume                  2
_journal_year                    2017
_chemical_absolute_configuration unk
_chemical_formula_sum            'C17 H26 N2 O3'
_chemical_formula_weight         306.4
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   constr
_audit_creation_date             2017-02-07T13:38:04-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   5.09990(10)
_cell_length_b                   15.0074(6)
_cell_length_c                   23.3654(9)
_cell_measurement_reflns_used    12983
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      23.9940
_cell_measurement_theta_min      4.0190
_cell_volume                     1788.30(11)
_computing_cell_refinement       'CrysAlisPro 1.171.38.43b (Rigaku OD, 2015)'
_computing_data_collection       'CrysAlisPro 1.171.38.43b (Rigaku OD, 2015)'
_computing_data_reduction        'CrysAlisPro 1.171.38.43b (Rigaku OD, 2015)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_environment      air
_diffrn_ambient_temperature      298(2)
_diffrn_detector                 'CCD plate'
_diffrn_detector_area_resol_mean 5.2923
_diffrn_detector_type            AtlasS2
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.967
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, AtlasS2'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0365
_diffrn_reflns_av_unetI/netI     0.0265
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.967
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            39824
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.944
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         29.716
_diffrn_reflns_theta_min         3.488
_diffrn_source                   'micro-focus sealed X-ray tube'
_diffrn_source_type              'SuperNova (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.078
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.45056
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.38.43b (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.138
_exptl_crystal_description       prism
_exptl_crystal_F_000             664
_exptl_crystal_size_max          0.961
_exptl_crystal_size_mid          0.304
_exptl_crystal_size_min          0.119
_refine_diff_density_max         0.406
_refine_diff_density_min         -0.169
_refine_diff_density_rms         0.039
_refine_ls_abs_structure_details
;
 Flack x determined using 1142 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.4(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.072
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         4781
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.072
_refine_ls_R_factor_all          0.0852
_refine_ls_R_factor_gt           0.0594
_refine_ls_shift/su_max          0
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0792P)^2^+0.3806P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1638
_refine_ls_wR_factor_ref         0.1802
_reflns_Friedel_coverage         0.686
_reflns_Friedel_fraction_full    1
_reflns_Friedel_fraction_max     0.913
_reflns_number_gt                3397
_reflns_number_total             4781
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ao7b00523_si_002.cif
_cod_data_source_block           new3
_cod_database_code               4516880
_oxdiff_exptl_absorpt_empirical_full_min 0.360
_oxdiff_exptl_absorpt_empirical_full_max 1.349
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
- Detector area scaling
;
_shelx_res_checksum              41979
_shelx_hkl_checksum              39023