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_4518834
_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 rm
_chemical_formula_moiety         'C43 H57 N4 O5, H2 O'
_chemical_formula_sum            'C43 H54 N4 O6'
_chemical_formula_weight         722.90
_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   mixed
_audit_creation_method           SHELXL-2018/3
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            12
_cell_length_a                   21.993(3)
_cell_length_b                   54.505(6)
_cell_length_c                   10.1583(11)
_cell_measurement_reflns_used    3201
_cell_measurement_temperature    250(2)
_cell_measurement_theta_max      50.76
_cell_measurement_theta_min      3.154
_cell_volume                     12177(3)
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution
;
SIR2004: Burla, M.C., Caliandro, R., Camalli, M., Carrozzini, B., 
Cascarano, G.L., De Caro, L., Giacovazzo, C., Polidori, G., Siliqi, 
D., Spagna, R. (2007). J. Appl. Cryst. 40, 609-613.
;
_diffrn_ambient_temperature      250(2)
_diffrn_detector_area_resol_mean 8.25
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\j and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.2555
_diffrn_reflns_av_unetI/netI     0.2360
_diffrn_reflns_Laue_measured_fraction_full 0.986
_diffrn_reflns_Laue_measured_fraction_max 0.986
_diffrn_reflns_limit_h_max       22
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       54
_diffrn_reflns_limit_k_min       -55
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            49964
_diffrn_reflns_point_group_measured_fraction_full 0.985
_diffrn_reflns_point_group_measured_fraction_max 0.985
_diffrn_reflns_theta_full        53.536
_diffrn_reflns_theta_max         53.536
_diffrn_reflns_theta_min         2.166
_diffrn_source                   'Cu Incoatec microsource'
_exptl_absorpt_coefficient_mu    0.632
_exptl_absorpt_correction_T_max  0.7505
_exptl_absorpt_correction_T_min  0.5736
_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    1.183
_exptl_crystal_description       parallelepiped
_exptl_crystal_F_000             4656
_exptl_crystal_size_max          0.160
_exptl_crystal_size_mid          0.071
_exptl_crystal_size_min          0.040
_refine_diff_density_max         0.367
_refine_diff_density_min         -0.266
_refine_diff_density_rms         0.070
_refine_ls_abs_structure_details
;
 Flack x determined using 1889 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.2(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.988
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1454
_refine_ls_number_reflns         14279
_refine_ls_number_restraints     2075
_refine_ls_restrained_S_all      0.954
_refine_ls_R_factor_all          0.1788
_refine_ls_R_factor_gt           0.0877
_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^)+(0.0946P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1811
_refine_ls_wR_factor_ref         0.2249
_reflns_Friedel_coverage         0.794
_reflns_Friedel_fraction_full    0.984
_reflns_Friedel_fraction_max     0.984
_reflns_number_gt                7529
_reflns_number_total             14279
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ao1c00745_si_002.cif
_cod_data_source_block           voacamina_ch_paper
_cod_original_cell_volume        12177(2)
_cod_database_code               4518834
_shelx_estimated_absorpt_t_min   0.906
_shelx_estimated_absorpt_t_max   0.975
_shelx_res_checksum              81912
_shelx_hkl_checksum              51477