Synthesis of (-)-PNU-286607 by Asymmetric Cyclization of Alkylidene Barbiturates
J. Craig Ruble; Alexander R. Hurd; Timothy A. Johnson; Debra A. Sherry; Michael R. Barbachyn; Peter L. Toogood; Gordon L. Bundy; David R. Graber; Gregg M. Kamilar; Journal of the American Chemical Society 131 (2009) 3991–3997; doi:10.1021/ja808014h

data_4104047
_publ_section_title
;
 Synthesis of (-)-PNU-286607 by Asymmetric Cyclization of Alkylidene
 Barbiturates
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              3991
_journal_page_last               3997
_journal_paper_doi               10.1021/ja808014h
_journal_volume                  131
_journal_year                    2009
_chemical_formula_sum            'C17 H18 N4 O6'
_chemical_formula_weight         374.35
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 116.324(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   22.5453(7)
_cell_length_b                   10.6236(3)
_cell_length_c                   17.5931(6)
_cell_measurement_temperature    293(2)
_cell_volume                     3776.8(2)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.969
_diffrn_measured_fraction_theta_max 0.969
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0839
_diffrn_reflns_av_sigmaI/netI    0.0580
_diffrn_reflns_limit_h_max       23
_diffrn_reflns_limit_h_min       -24
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            10412
_diffrn_reflns_theta_full        58.87
_diffrn_reflns_theta_max         58.87
_diffrn_reflns_theta_min         4.38
_exptl_absorpt_coefficient_mu    0.859
_exptl_crystal_density_diffrn    1.317
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1568
_refine_diff_density_max         0.242
_refine_diff_density_min         -0.290
_refine_diff_density_rms         0.059
_refine_ls_extinction_coef       0.00016(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.864
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     279
_refine_ls_number_reflns         2623
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.864
_refine_ls_R_factor_all          0.0612
_refine_ls_R_factor_gt           0.0431
_refine_ls_shift/su_max          0.095
_refine_ls_shift/su_mean         0.009
_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          0.1113
_refine_ls_wR_factor_ref         0.1269
_reflns_number_gt                1926
_reflns_number_total             2623
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ja808014h_si_001.cif
_cod_data_source_block           drg10a
_cod_database_code               4104047