Stereospecific Approach to the Synthesis of Ring-A Oxygenated Sarpagine Indole Alkaloids. Total Synthesis of the Dimeric Indole Alkaloid P-(+)-Dispegatrine and Six Other Monomeric Indole Alkaloids
Chitra R. Edwankar; Rahul V. Edwankar; Ojas A. Namjoshi; Xuebin Liao; James M. Cook; Journal of Organic Chemistry 78 (2013) 6471–6487; doi:10.1021/jo400469t

data_4028384
_publ_section_title
;
 Stereospecific Approach to the Synthesis of Ring-A Oxygenated Sarpagine
 Indole Alkaloids. Total Synthesis of the Dimeric Indole Alkaloid
 P-(+)-Dispegatrine and Six Other Monomeric Indole Alkaloids
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              6471
_journal_page_last               6487
_journal_paper_doi               10.1021/jo400469t
_journal_volume                  78
_journal_year                    2013
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C19 H20 N2 O2'
_chemical_formula_sum            'C19 H20 N2 O2'
_chemical_formula_weight         308.37
_space_group_IT_number           9
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'C -2yc'
_symmetry_space_group_name_H-M   'C 1 c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 99.4900(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   24.0196(12)
_cell_length_b                   7.2186(4)
_cell_length_c                   9.3086(5)
_cell_measurement_reflns_used    6899
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      30.53
_cell_measurement_theta_min      2.95
_cell_volume                     1591.91(15)
_computing_cell_refinement       'Bruker APEX2 v2008.4-0 (Bruker, 2007)'
_computing_data_collection       'Bruker APEX2 v2008.4-0 (Bruker, 2007)'
_computing_data_reduction
;
Bruker SAINT v7.53A (Bruker, 2007), Bruker XPREP v2008/2 (Bruker, 2007)
;
_computing_molecular_graphics    'Bruker SHELXTL v6.12 (Bruker, 2000b)'
_computing_publication_material  'Bruker SHELXTL v6.12 (Bruker, 2000b)'
_computing_structure_refinement  'Bruker SHELXTL v6.12 (Bruker, 2000b)'
_computing_structure_solution    'Bruker SHELXTL v6.12 (Bruker, 2000b)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.953
_diffrn_measurement_device_type  'Bruker SMART APEX II CCD'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0137
_diffrn_reflns_av_sigmaI/netI    0.0189
_diffrn_reflns_limit_h_max       33
_diffrn_reflns_limit_h_min       -33
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            9153
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         30.53
_diffrn_reflns_theta_min         1.72
_exptl_absorpt_coefficient_mu    0.084
_exptl_absorpt_correction_T_max  0.9920
_exptl_absorpt_correction_T_min  0.9489
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS v2.10 (Bruker, 2000c)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.287
_exptl_crystal_description       plate
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.629
_exptl_crystal_size_mid          0.486
_exptl_crystal_size_min          0.095
_refine_diff_density_max         0.340
_refine_diff_density_min         -0.234
_refine_diff_density_rms         0.044
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.4(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.861
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     209
_refine_ls_number_reflns         4465
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      0.861
_refine_ls_R_factor_all          0.0345
_refine_ls_R_factor_gt           0.0339
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0782P)^2^+0.7851P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0928
_refine_ls_wR_factor_ref         0.0934
_reflns_number_gt                4392
_reflns_number_total             4465
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            jo400469t_si_002.cif
_cod_data_source_block           cook88
_cod_original_sg_symbol_H-M      'C c'
_cod_database_code               4028384