Base-promoted annulation of α-hydroxy ketones and dimethyl but-2-ynedioate: straightforward access to pyrano[4,3-a]quinolizine-1,4,6(2H)-triones and 2H-pyran-2,5(6H)-diones.
He, Haitao; Qi, Chaorong; Ou, Yanglu; Xiong, Wenfang; Hu, Xiaohan; Ren, Yanwei; Jiang, Huanfeng; Organic & biomolecular chemistry 12 (2014) 8128–8131; doi:10.1039/c4ob01858c

data_7154035
_publ_section_title
;
 Base-promoted annulation of \a-hydroxy ketones and dimethyl
 but-2-ynedioate: straightforward access to
 pyrano[4,3-a]quinolizine-1,4,6(2H)-triones and 2H-pyran-2,5(6H)-diones.
;
_journal_issue                   41
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              8128
_journal_page_last               8131
_journal_paper_doi               10.1039/c4ob01858c
_journal_volume                  12
_journal_year                    2014
_chemical_formula_sum            'C14 H11 N O4'
_chemical_formula_weight         257.24
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           14
_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                 110.65(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.3551(15)
_cell_length_b                   19.227(4)
_cell_length_c                   8.7515(18)
_cell_measurement_temperature    293(2)
_cell_volume                     1158.1(5)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.980
_diffrn_measured_fraction_theta_max 0.980
_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  0.0245
_diffrn_reflns_av_sigmaI/netI    0.0237
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -24
_diffrn_reflns_limit_l_max       11
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            10380
_diffrn_reflns_theta_full        27.45
_diffrn_reflns_theta_max         27.45
_diffrn_reflns_theta_min         3.14
_exptl_absorpt_coefficient_mu    0.110
_exptl_crystal_density_diffrn    1.475
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             536
_refine_diff_density_max         0.237
_refine_diff_density_min         -0.318
_refine_diff_density_rms         0.086
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.077
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     172
_refine_ls_number_reflns         2606
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.077
_refine_ls_R_factor_all          0.0616
_refine_ls_R_factor_gt           0.0456
_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^)+(0.0954P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1347
_refine_ls_wR_factor_ref         0.1496
_reflns_number_gt                1904
_reflns_number_total             2606
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c4ob01858c2.cif
_cod_data_source_block           qi-1
_cod_depositor_comments          'Adding full bibliography for 7154035.cif.'
_cod_original_cell_volume        1158.1(4)
_cod_database_code               7154035