Concise construction of the tetracyclic core of lycorine-type alkaloids and the formal synthesis of α-lycorane based on asymmetric bifunctional thiourea-catalyzed cascade reaction.
Wang, Yao; Luo, Yong-Chun; Zhang, Hong-Bo; Xu, Peng-Fei; Organic & biomolecular chemistry 10 (2012) 8211–8215; doi:10.1039/c2ob26422f

data_7152699
_publ_section_title
;
 Concise construction of the tetracyclic core of lycorine-type alkaloids
 and the formal synthesis of \a-lycorane based on asymmetric bifunctional
 thiourea-catalyzed cascade reaction.
;
_journal_issue                   41
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              8211
_journal_page_last               8215
_journal_paper_doi               10.1039/c2ob26422f
_journal_volume                  10
_journal_year                    2012
_chemical_formula_sum            'C20 H24 Br N O8'
_chemical_formula_weight         486.31
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.122(6)
_cell_length_b                   10.799(6)
_cell_length_c                   20.017(11)
_cell_measurement_reflns_used    2508
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      21.95
_cell_measurement_theta_min      2.25
_cell_volume                     2188(2)
_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 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.1177
_diffrn_reflns_av_sigmaI/netI    0.1250
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            11119
_diffrn_reflns_theta_full        25.50
_diffrn_reflns_theta_max         25.50
_diffrn_reflns_theta_min         2.03
_exptl_absorpt_coefficient_mu    1.924
_exptl_absorpt_correction_T_max  0.707
_exptl_absorpt_correction_T_min  0.636
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.476
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Block
_exptl_crystal_F_000             1000
_exptl_crystal_size_max          0.24
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.422
_refine_diff_density_min         -0.641
_refine_diff_density_rms         0.077
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.000(19)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.767
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     269
_refine_ls_number_reflns         4039
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.767
_refine_ls_R_factor_all          0.1185
_refine_ls_R_factor_gt           0.0546
_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^)+(0.1468P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1393
_refine_ls_wR_factor_ref         0.1905
_reflns_number_gt                2275
_reflns_number_total             4039
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob26422f.txt
_cod_data_source_block           xpf
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7152699