Transition-Metal-Free Total Synthesis and Revision of the Absolute Configuration of Pipermethystine.
Vázquez-Amaya, Laura Y; Quintero, Leticia; Rodríguez-Molina, Braulio; Sartillo-Piscil, Fernando; The Journal of organic chemistry  (2020) –; doi:10.1021/acs.joc.9b03218

data_4037907
_publ_section_title
;
 Transition-Metal-Free Total Synthesis and Revision of the Absolute
 Configuration of Pipermethystine.
;
_journal_name_full               'The Journal of organic chemistry'
_journal_paper_doi               10.1021/acs.joc.9b03218
_journal_year                    2020
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C14 H17 N O3'
_chemical_formula_sum            'C14 H17 N O3'
_chemical_formula_weight         247.28
_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   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2018/3
_cell_angle_alpha                90
_cell_angle_beta                 99.521(3)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.6068(6)
_cell_length_b                   6.5971(4)
_cell_length_c                   20.9560(14)
_cell_measurement_reflns_used    9881
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      79.39
_cell_measurement_theta_min      4.28
_cell_volume                     1309.83(14)
_computing_cell_refinement       'APEX3 v2018.1-0(Bruker, 2018)'
_computing_data_collection       'APEX3 v2018.1-0(Bruker, 2018)'
_computing_data_reduction        'SAINT V8.38A (Bruker, 2014)'
_computing_molecular_graphics    'SHELXLe (Hubschle et al, 2011)'
_computing_publication_material  'CIFTAB V 2013/2 (Sheldrick, 2013)'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXS-2012 (Bruker, 2013)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 52.0833
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type
'Bruker D8 Venture \k-geometry diffractometer 208039-1'
_diffrn_measurement_method       '\f and \w-scans'
_diffrn_radiation_monochromator  'Helios multilayer mirror'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0579
_diffrn_reflns_av_unetI/netI     0.0251
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            50484
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.985
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         79.833
_diffrn_reflns_theta_min         2.138
_diffrn_source                   'micro-focus X-ray source'
_exptl_absorpt_coefficient_mu    0.719
_exptl_absorpt_correction_T_max  0.7543
_exptl_absorpt_correction_T_min  0.6465
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(Sheldrick, 2012)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.254
_exptl_crystal_description       platy-prism
_exptl_crystal_F_000             528
_exptl_crystal_size_max          0.404
_exptl_crystal_size_mid          0.264
_exptl_crystal_size_min          0.060
_refine_diff_density_max         0.158
_refine_diff_density_min         -0.149
_refine_diff_density_rms         0.031
_refine_ls_abs_structure_details
;
 Flack x determined using 2106 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.01(19)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.081
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     333
_refine_ls_number_reflns         5626
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.081
_refine_ls_R_factor_all          0.0450
_refine_ls_R_factor_gt           0.0394
_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^)+(0.0345P)^2^+0.3859P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0874
_refine_ls_wR_factor_ref         0.0914
_reflns_Friedel_coverage         0.811
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.968
_reflns_number_gt                5134
_reflns_number_total             5626
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo9b03218_si_002.cif
_cod_data_source_block           131RMB19
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4037907
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.760
_shelx_estimated_absorpt_t_max   0.958
_shelx_res_checksum              70110
_shelx_hkl_checksum              43995