An approach to the skeleton of aspidophylline a.
Li, Qi; Li, Guang; Ma, Shaobo; Feng, Pengju; Shi, Yian; Organic letters 15 (2013) 2601–2603; doi:10.1021/ol4007713

data_1512033
_publ_section_title
;
 An approach to the skeleton of aspidophylline a.
;
_journal_issue                   11
_journal_name_full               'Organic letters'
_journal_page_first              2601
_journal_page_last               2603
_journal_paper_doi               10.1021/ol4007713
_journal_volume                  15
_journal_year                    2013
_chemical_formula_moiety         'C17 H18 N4 O3'
_chemical_formula_sum            'C17 H18 N4 O3'
_chemical_formula_weight         326.35
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/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                 106.285(7)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.743(4)
_cell_length_b                   20.491(10)
_cell_length_c                   10.441(6)
_cell_measurement_reflns_used    5434
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      27.4851
_cell_measurement_theta_min      2.0321
_cell_volume                     1590.1(15)
_computing_cell_refinement       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_collection       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_reduction        'CrystalClear (Rigaku Inc., 2008)'
_computing_molecular_graphics
;
 Mercury: visualization and analysis of crystal structures, C. F. Macrae,
 P. R. Edgington, P. McCabe, E. Pidcock, G. P. Shields, R. Taylor,
 M. Towler and J. van de Streek, J. Appl. Cryst., 39, 453-457, 2006.
;
_computing_publication_material  'SHELX-97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELX-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELX-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 28.5714
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_diffrn_measurement_device_type  'Saturn724+ CCD'
_diffrn_measurement_method       '\w scans at fixed \c = 45\%'
_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  0.0389
_diffrn_reflns_av_sigmaI/netI    0.0345
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       -26
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            10349
_diffrn_reflns_theta_full        27.53
_diffrn_reflns_theta_max         27.53
_diffrn_reflns_theta_min         1.99
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.6814
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrystalClear (Rigaku Inc., 2008)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.363
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             688
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.706
_refine_diff_density_min         -0.636
_refine_diff_density_rms         0.182
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   2.354
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     218
_refine_ls_number_reflns         3612
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      2.354
_refine_ls_R_factor_all          0.1123
_refine_ls_R_factor_gt           0.0958
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2674
_refine_ls_wR_factor_ref         0.3161
_reflns_number_gt                3278
_reflns_number_total             3612
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol4007713_si_003.cif
_cod_data_source_block           sa2391
_cod_original_cell_volume        1590.1(14)
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               1512033