Collective synthesis of aspulvinone and its analogues by vinylogous aldol condensation of substituted tetronic acids with aldehydes.
Yu, Xiaotan; Gu, Xiaoxia; Zhao, Yunpeng; Wang, Fengqing; Sun, Weiguang; Qi, Changxing; Gu, Lianghu; Zhang, Yonghui; RSC advances 13 (2023) 4859–4864; doi:10.1039/d2ra08133d

data_7246392
_publ_section_title
;
 Collective synthesis of aspulvinone and its analogues by vinylogous aldol
 condensation of substituted tetronic acids with aldehydes.
;
_journal_issue                   7
_journal_name_full               'RSC advances'
_journal_page_first              4859
_journal_page_last               4864
_journal_paper_doi               10.1039/d2ra08133d
_journal_volume                  13
_journal_year                    2023
_chemical_absolute_configuration unk
_chemical_formula_sum            'C20 H18 O5'
_chemical_formula_weight         338.34
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2022-09-01 deposited with the CCDC.	2023-01-30 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 94.087(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.9556(2)
_cell_length_b                   7.1740(2)
_cell_length_c                   18.9601(4)
_cell_measurement_reflns_used    22978
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      73.639
_cell_measurement_theta_min      4.239
_cell_volume                     1622.06(6)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  ccd
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_unetI/netI     0.0131
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            10514
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.992
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         73.910
_diffrn_reflns_theta_min         3.706
_exptl_absorpt_coefficient_mu    0.821
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.385
_exptl_crystal_description       Block
_exptl_crystal_F_000             712
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.200
_exptl_transmission_factor_max   0.864
_exptl_transmission_factor_min   0.864
_refine_diff_density_max         0.180
_refine_diff_density_min         -0.266
_refine_diff_density_rms         0.059
_refine_ls_abs_structure_details
;
 Classical Flack method preferred over Parsons because s.u. lower.
;
_refine_ls_abs_structure_Flack   0.45(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.867
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     458
_refine_ls_number_reflns         10514
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.867
_refine_ls_R_factor_all          0.0420
_refine_ls_R_factor_gt           0.0415
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1108P)^2^+0.3077P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1172
_refine_ls_wR_factor_ref         0.1179
_reflns_Friedel_coverage         0.841
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.989
_reflns_number_gt                10275
_reflns_number_total             10514
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d2ra08133d2.cif
_cod_data_source_block           0323_YXT-1_twin1_hklf5
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               7246392
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.853
_shelx_estimated_absorpt_t_max   0.853
_shelx_res_checksum              9071