Synthesis of Functionalized Chromene and Chroman Derivatives via Cesium Carbonate Promoted Formal [4 + 2] Annulation of 2'-Hydroxychalcones with Allenoates.
Rouh, Hossein; Liu, Yangxue; Katakam, Nandakumar; Pham, Lilian; Zhu, Yi-Long; Li, Guigen; The Journal of organic chemistry 83 (2018) 15372–15379; doi:10.1021/acs.joc.8b02627

data_4034742
_publ_section_title
;
 Synthesis of Functionalized Chromene and Chroman Derivatives via Cesium
 Carbonate Promoted Formal [4 + 2] Annulation of 2'-Hydroxychalcones with
 Allenoates.
;
_journal_issue                   24
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              15372
_journal_page_last               15379
_journal_paper_doi               10.1021/acs.joc.8b02627
_journal_volume                  83
_journal_year                    2018
_chemical_formula_sum            'C26 H22 O4'
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_space_group_name_H-M_alt        'C 1 2/c 1'
_symmetry_cell_setting           monoclinic
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_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/c 1'
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_audit_creation_date             2018-08-01T14:58:18-00:00
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_cell_angle_beta                 104.542(2)
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_cell_length_c                   37.416(6)
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_cell_measurement_theta_max      25.48
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_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
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_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
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_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.136
_diffrn_reflns_theta_min         1.124
_exptl_absorpt_coefficient_mu    0.09
_exptl_absorpt_correction_T_max  0.7455
_exptl_absorpt_correction_T_min  0.6969
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
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_refine_ls_restrained_S_all      1.053
_refine_ls_R_factor_all          0.0573
_refine_ls_R_factor_gt           0.0401
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0356P)^2^+1.6944P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
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_reflns_threshold_expression     'I > 2\s(I)'
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_cod_data_source_block           li18_08
_cod_original_cell_volume        3941.6(10)
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               4034742
_shelx_estimated_absorpt_t_min   0.958
_shelx_estimated_absorpt_t_max   0.991
_shelx_res_checksum              96397
_shelx_hkl_checksum              6147