BF3•OEt2-Catalyzed synthesis of 2,2'-spirobi-2H-1-benzopyrans from 2H-chromenes
Mudulkar, Sairam; Kolla, Sai Teja; Balasubramanian, Sridhar; Bhimapaka, China Raju; Organic & Biomolecular Chemistry  (2022) –; doi:10.1039/D2OB01286C

data_7158918
_publ_section_title
;
 BF3&#x2022;OEt2-Catalyzed synthesis of 2,2'-spirobi-2H-1-benzopyrans from
 2H-chromenes
;
_journal_name_full               'Organic &amp; Biomolecular Chemistry'
_journal_paper_doi               10.1039/D2OB01286C
_journal_year                    2022
_chemical_formula_moiety         'C21 H17 Cl O4'
_chemical_formula_sum            'C21 H17 Cl O4'
_chemical_formula_weight         368.80
_chemical_name_systematic
'Ethyl 3'-chloro-6'-methyl-2,2'-spirobi[chromene]-3-carboxylate'
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2016-09-01 deposited with the CCDC.	2022-10-04 downloaded from the CCDC.
;
_cell_angle_alpha                92.8500(10)
_cell_angle_beta                 111.8700(10)
_cell_angle_gamma                95.7020(10)
_cell_formula_units_Z            2
_cell_length_a                   8.7937(7)
_cell_length_b                   10.0005(8)
_cell_length_c                   11.2448(9)
_cell_measurement_reflns_used    4994
_cell_measurement_temperature    294(2)
_cell_measurement_theta_max      27.57
_cell_measurement_theta_min      2.52
_cell_volume                     909.14(13)
_computing_cell_refinement       'SAINT (Bruker, 2001)'
_computing_data_collection       'SMART (Bruker, 2001)'
_computing_data_reduction        'SAINT (Bruker, 2001)'
_computing_molecular_graphics    'SHELXL2014 (Sheldrick, 2015)'
_computing_publication_material  'SHELXL2014 (Sheldrick, 2015)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXL-2014/7 (Sheldrick, 2015)'
_diffrn_ambient_temperature      294(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.930
_diffrn_measurement_device_type  'Bruker SMART APEX CCD area-detector'
_diffrn_measurement_method       \w
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0180
_diffrn_reflns_av_unetI/netI     0.0200
_diffrn_reflns_Laue_measured_fraction_full 0.997
_diffrn_reflns_Laue_measured_fraction_max 0.930
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            10400
_diffrn_reflns_point_group_measured_fraction_full 0.997
_diffrn_reflns_point_group_measured_fraction_max 0.930
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.378
_diffrn_reflns_theta_min         1.960
_exptl_absorpt_coefficient_mu    0.233
_exptl_absorpt_correction_T_max  0.98
_exptl_absorpt_correction_T_min  0.92
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS; Bruker,2001'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.347
_exptl_crystal_description       block
_exptl_crystal_F_000             384
_exptl_crystal_size_max          0.160
_exptl_crystal_size_mid          0.150
_exptl_crystal_size_min          0.060
_refine_diff_density_max         0.258
_refine_diff_density_min         -0.180
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.041
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     237
_refine_ls_number_reflns         4239
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.0518
_refine_ls_R_factor_gt           0.0443
_refine_ls_shift/su_max          0.010
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0759P)^2^+0.1249P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1275
_refine_ls_wR_factor_ref         0.1351
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3483
_reflns_number_total             4239
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d2ob01286c2.cif
_cod_data_source_block           AZ86m
_cod_database_code               7158918
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.964
_shelx_estimated_absorpt_t_max   0.986
_shelx_res_checksum              18215
_shelx_hkl_checksum              71291