Diastereoselective intramolecular oxidopyrylium-alkene [5 + 2]-cycloaddition of substrates with a β-chiral center on alkene tethers: synthesis of 8-oxabicyclo-[3.2.1]-octenone heterocycles.
Ghosh, Arun K.; Hopkins, Denver; Organic & biomolecular chemistry 23 (2025) 10701–10723; doi:10.1039/d5ob01429h

data_7160853
_publ_section_title
;
 Diastereoselective intramolecular oxidopyrylium-alkene [5 +
 2]-cycloaddition of substrates with a &#x3b2;-chiral center on alkene
 tethers: synthesis of 8-oxabicyclo-[3.2.1]-octenone heterocycles.
;
_journal_issue                   47
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              10701
_journal_page_last               10723
_journal_paper_doi               10.1039/d5ob01429h
_journal_volume                  23
_journal_year                    2025
_chemical_formula_moiety         'C16 H16 O2'
_chemical_formula_sum            'C16 H16 O2'
_chemical_formula_weight         240.29
_chemical_name_systematic
;
2-phenyl-1,2,3,7,8,8a-hexahydro-4H-3a,7-epoxyazulen-4-one
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2019/3
_audit_update_record
;
2024-12-17 deposited with the CCDC.	2025-10-27 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 97.742(9)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.2958(11)
_cell_length_b                   10.1721(10)
_cell_length_c                   12.0183(16)
_cell_measurement_reflns_used    6502
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      79.0292
_cell_measurement_theta_min      6.1437
_cell_volume                     1247.2(2)
_computing_cell_refinement       'SAINT V8.40B (Bruker, 2020)'
_computing_data_collection       'Apex5 v2023.9-2 (Bruker, 2023)'
_computing_data_reduction        'SAINT V8.40B (Bruker, 2020)'
_computing_structure_refinement
;  
SHELXL-2019/2 (Sheldrick, 2015a, 2019), 
SHELXLE Rev1613 (H\"ubschle et al., 2011)
;
_computing_structure_solution    'SHELXT (Sheldrick, 2015b)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 7.4074
_diffrn_detector_type
'PhotonIII_C14 charge-integrating and photon counting pixel array'
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.981
_diffrn_measurement_device       'four circle diffractometer'
_diffrn_measurement_device_type  'Bruker AXS D8 Quest'
_diffrn_measurement_method       'omega and phi scans'
_diffrn_radiation_monochromator  'HELIOS multilayer Montel optics'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0818
_diffrn_reflns_av_unetI/netI     0.0729
_diffrn_reflns_Laue_measured_fraction_full 0.996
_diffrn_reflns_Laue_measured_fraction_max 0.981
_diffrn_reflns_number            2672
_diffrn_reflns_point_group_measured_fraction_full 0.996
_diffrn_reflns_point_group_measured_fraction_max 0.981
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         80.097
_diffrn_reflns_theta_min         5.720
_diffrn_source                   'I-mu-S 3.0 microsource X-ray tube'
_diffrn_source_current           '1.1 mA'
_diffrn_source_voltage           '50 kV'
_exptl_absorpt_coefficient_mu    0.660
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
TWINABS 2012/1: Krause, L., Herbst-Irmer, R., Sheldrick G.M. & Stalke D.
(2015). J. Appl. Cryst. 48 3-10.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.280
_exptl_crystal_description       plate
_exptl_crystal_F_000             512
_exptl_crystal_size_max          0.230
_exptl_crystal_size_mid          0.058
_exptl_crystal_size_min          0.010
_exptl_transmission_factor_max   0.754299
_exptl_transmission_factor_min   0.626708
_refine_diff_density_max         0.285
_refine_diff_density_min         -0.273
_refine_diff_density_rms         0.058
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.109
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     163
_refine_ls_number_reflns         2672
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.109
_refine_ls_R_factor_all          0.0808
_refine_ls_R_factor_gt           0.0565
_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^)+(0.0725P)^2^+0.7022P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1518
_refine_ls_wR_factor_ref         0.1657
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2081
_reflns_number_total             2672
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ob01429h2.cif
_cod_data_source_block           DRH_05_156_0m_4
_cod_depositor_comments
'Adding full bibliography for 7160851--7160853.cif.'
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               7160853
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_min   0.863
_shelx_estimated_absorpt_t_max   0.993
_shelx_res_checksum              11531