Intramolecular direct dehydrohalide coupling promoted by KO(t)Bu: total synthesis of Amaryllidaceae alkaloids anhydrolycorinone and oxoassoanine.
De, Subhadip; Ghosh, Santanu; Bhunia, Subhajit; Sheikh, Javeed Ahmad; Bisai, Alakesh; Organic letters 14 (2012) 4466–4469; doi:10.1021/ol3019677

data_1508616
_publ_section_title
;
 Intramolecular direct dehydrohalide coupling promoted by KO(t)Bu: total
 synthesis of Amaryllidaceae alkaloids anhydrolycorinone and oxoassoanine.
;
_journal_issue                   17
_journal_name_full               'Organic letters'
_journal_page_first              4466
_journal_page_last               4469
_journal_paper_doi               10.1021/ol3019677
_journal_volume                  14
_journal_year                    2012
_chemical_formula_sum            'C17 H15 N O3'
_chemical_formula_weight         281.30
_space_group_IT_number           4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 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                 110.690(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.4692(6)
_cell_length_b                   5.9128(4)
_cell_length_c                   12.8986(7)
_cell_measurement_temperature    296(2)
_cell_volume                     675.61(7)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_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  0.0179
_diffrn_reflns_av_sigmaI/netI    0.0239
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            6162
_diffrn_reflns_theta_full        27.44
_diffrn_reflns_theta_max         27.44
_diffrn_reflns_theta_min         2.30
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_T_max  0.967
_exptl_absorpt_correction_T_min  0.963
_exptl_absorpt_correction_type   'Empirical''Bruker SADABS V2.10'
_exptl_absorpt_process_details   'Bruker SADABS V2.10'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.383
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Block
_exptl_crystal_F_000             296
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.35
_refine_diff_density_max         0.172
_refine_diff_density_min         -0.176
_refine_diff_density_rms         0.034
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.6(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.611
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     228
_refine_ls_number_reflns         2906
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.611
_refine_ls_R_factor_all          0.0397
_refine_ls_R_factor_gt           0.0366
_refine_ls_shift/su_max          0.009
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.2000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1259
_refine_ls_wR_factor_ref         0.1351
_reflns_number_gt                2690
_reflns_number_total             2906
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol3019677_si_002.cif
_cod_data_source_block           subahadip_0m
_cod_original_sg_symbol_H-M      P21
_cod_database_code               1508616