Synthesis of pyrano[3,2-<i>c</i>]chromene-2,5-diones from 4-hydroxycoumarins and aminocrotonates under solvent-free conditions.
Begum, Shahnaz; Kashameni, Sravani; Sridhar, Balasubramanian; Atmakur, Krishnaiah; Bhimapaka, China Raju; Organic & biomolecular chemistry 23 (2025) 1443–1447; doi:10.1039/d4ob01800a

data_7160306
_publ_section_title
;
 Synthesis of pyrano[3,2-<i>c</i>]chromene-2,5-diones from
 4-hydroxycoumarins and aminocrotonates under solvent-free conditions.
;
_journal_issue                   6
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1443
_journal_page_last               1447
_journal_paper_doi               10.1039/d4ob01800a
_journal_volume                  23
_journal_year                    2025
_chemical_formula_moiety         'C19 H12 O4'
_chemical_formula_sum            'C19 H12 O4'
_chemical_formula_weight         304.29
_space_group_crystal_system      monoclinic
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_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2019/2
_audit_update_record
;
2024-07-17 deposited with the CCDC.	2024-12-19 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 92.317(3)
_cell_angle_gamma                90
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_cell_measurement_theta_min      2.9785
_cell_volume                     1426.95(12)
_computing_cell_refinement       '<i>SAINT</i> (Bruker, 2016)'
_computing_data_collection       '<i>APEX3</i> (Bruker, 2016)'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
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_diffrn_ambient_temperature      294(2)
_diffrn_measured_fraction_theta_full 0.999
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_diffrn_measurement_device_type  'Bruker D8 QUEST PHOTON-100'
_diffrn_measurement_method       '\w and \f'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0300
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_diffrn_reflns_Laue_measured_fraction_full 0.999
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_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
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_diffrn_reflns_limit_k_min       -10
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_diffrn_reflns_limit_l_min       -36
_diffrn_reflns_number            15912
_diffrn_reflns_point_group_measured_fraction_full 0.999
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_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.278
_diffrn_reflns_theta_min         2.636
_exptl_absorpt_coefficient_mu    0.100
_exptl_absorpt_correction_T_max  0.7457
_exptl_absorpt_correction_T_min  0.6828
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
 SADABS 2016/2: Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D.,
 J. Appl. Cryst. 48 (2015) 3-10
;
_exptl_crystal_colour            colourless
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_exptl_crystal_description       block
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_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.160
_refine_diff_density_max         0.171
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_refine_diff_density_rms         0.038
_refine_ls_extinction_method     none
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_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
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_refine_ls_number_reflns         3541
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.029
_refine_ls_R_factor_all          0.0821
_refine_ls_R_factor_gt           0.0455
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0476P)^2^+0.4094P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1066
_refine_ls_wR_factor_ref         0.1266
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2302
_reflns_number_total             3541
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d4ob01800a2.cif
_cod_data_source_block           KB1285_0m
_cod_depositor_comments          'Adding full bibliography for 7160306.cif.'
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               7160306
_shelx_shelxl_version_number     2019/2
_shelx_estimated_absorpt_t_min   0.977
_shelx_estimated_absorpt_t_max   0.984
_shelx_res_checksum              81834
_shelx_hkl_checksum              80510