Efficient Access to the Iboga Skeleton: Optimized Procedure to Obtain Voacangine from Voacanga africana Root Bark
González, Bruno; Fagúndez, Catherine; Peixoto de Abreu Lima, Alejandro; Suescun, Leopoldo; Sellanes, Diver; Seoane, Gustavo A.; Carrera, Ignacio; ACS Omega  (2021) –; doi:10.1021/acsomega.1c00745

data_4518833
_publ_section_title
;
 Efficient Access to the Iboga Skeleton: Optimized Procedure to Obtain
 Voacangine from Voacanga africana Root Bark
;
_journal_name_full               'ACS Omega'
_journal_paper_doi               10.1021/acsomega.1c00745
_journal_year                    2021
_chemical_absolute_configuration rmad
_chemical_formula_moiety         'C43 H57 N4 O5, 2.5(H2 O)'
_chemical_formula_sum            'C43 H57 N4 O7.5'
_chemical_formula_weight         749.92
_chemical_name_common            voacamine
_space_group_crystal_system      orthorhombic
_space_group_IT_number           18
_space_group_name_Hall           'P 2 2ab'
_space_group_name_H-M_alt        'P 21 21 2'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2018/3
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   18.7939(10)
_cell_length_b                   22.4746(12)
_cell_length_c                   10.3719(5)
_cell_measurement_reflns_used    9443
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      67.657
_cell_measurement_theta_min      3.65
_cell_volume                     4380.9(4)
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      298(2)
_diffrn_detector_area_resol_mean 10.4167
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Bruker D8 Venture/Photon 100 CMOS'
_diffrn_measurement_method       '\j and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0965
_diffrn_reflns_av_unetI/netI     0.0298
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -22
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -27
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            169742
_diffrn_reflns_point_group_measured_fraction_full 0.992
_diffrn_reflns_point_group_measured_fraction_max 0.986
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         68.927
_diffrn_reflns_theta_min         3.065
_diffrn_source                   'Cu Incoatec microsource'
_exptl_absorpt_coefficient_mu    0.628
_exptl_absorpt_correction_T_max  0.7531
_exptl_absorpt_correction_T_min  0.6735
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 SADABS 2016/2: Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D.,
 J. Appl. Cryst. 48 (2015) 3-10
;
_exptl_crystal_colour            'light pink'
_exptl_crystal_density_diffrn    1.137
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             1612
_exptl_crystal_size_max          0.310
_exptl_crystal_size_mid          0.283
_exptl_crystal_size_min          0.130
_refine_diff_density_max         0.540
_refine_diff_density_min         -0.292
_refine_diff_density_rms         0.069
_refine_ls_abs_structure_details
;
 Flack x determined using 1746 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.01(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.071
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     874
_refine_ls_number_reflns         8023
_refine_ls_number_restraints     1572
_refine_ls_restrained_S_all      1.034
_refine_ls_R_factor_all          0.1552
_refine_ls_R_factor_gt           0.1276
_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^)+(0.1657P)^2^+5.3190P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.3400
_refine_ls_wR_factor_ref         0.3659
_reflns_Friedel_coverage         0.778
_reflns_Friedel_fraction_full    0.985
_reflns_Friedel_fraction_max     0.976
_reflns_number_gt                5663
_reflns_number_total             8023
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ao1c00745_si_002.cif
_cod_data_source_block           voacamina_uy_paper
_cod_original_formula_sum        'C43 H57 N4 O7.50'
_cod_database_code               4518833
_shelx_estimated_absorpt_t_min   0.829
_shelx_estimated_absorpt_t_max   0.923
_shelx_res_checksum              93206
_shelx_hkl_checksum              97985