π(4)s + π(2)s Cycloaddition of Spiroepoxycyclohexa-2,4-dienone, Radical Cyclization, and Oxidation-Aldol-Oxidation Cascade: Synthesis of BCDE Ring of Atropurpuran.
Jarhad, Dnyandev B.; Singh, Vishwakarma; The Journal of organic chemistry 81 (2016) 4304–4309; doi:10.1021/acs.joc.6b00728

data_4036859
_publ_section_title
;
 \p(4)s + \p(2)s Cycloaddition of Spiroepoxycyclohexa-2,4-dienone, Radical
 Cyclization, and Oxidation-Aldol-Oxidation Cascade: Synthesis of BCDE
 Ring of Atropurpuran.
;
_journal_issue                   10
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              4304
_journal_page_last               4309
_journal_paper_doi               10.1021/acs.joc.6b00728
_journal_volume                  81
_journal_year                    2016
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C20 H24 O6'
_chemical_formula_sum            'C20 H24 O6'
_chemical_formula_weight         360.41
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90.0000
_cell_angle_beta                 103.741(3)
_cell_angle_gamma                90.0000
_cell_formula_units_Z            2
_cell_length_a                   10.351(3)
_cell_length_b                   7.7827(18)
_cell_length_c                   11.328(3)
_cell_measurement_reflns_used    3487
_cell_measurement_temperature    150
_cell_measurement_theta_max      29.20
_cell_measurement_theta_min      3.10
_cell_volume                     886.5(4)
_computing_cell_refinement       'CrystalClear-SM Expert 2.1 b28'
_computing_data_collection       'CrystalClear-SM Expert 2.1 b28 (Rigaku, 2013)'
_computing_data_reduction        'CrystalClear-SM Expert 2.1 b28'
_computing_molecular_graphics    'CrystalStructure 4.0'
_computing_publication_material  'CrystalStructure 4.0 (Rigaku, 2010)'
_computing_structure_refinement  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      150
_diffrn_detector_area_resol_mean 7.111
_diffrn_measured_fraction_theta_full 0.993
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'Rigaku Saturn724'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71070
_diffrn_reflns_av_R_equivalents  0.0754
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            12115
_diffrn_reflns_theta_full        29.16
_diffrn_reflns_theta_max         29.16
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.099
_exptl_absorpt_correction_T_max  0.975
_exptl_absorpt_correction_T_min  0.961
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'NUMABS (Rigaku, 1999)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.350
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             384.00
_exptl_crystal_size_max          0.390
_exptl_crystal_size_mid          0.390
_exptl_crystal_size_min          0.260
_refine_diff_density_max         0.470
_refine_diff_density_min         -0.280
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.678
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     235
_refine_ls_number_reflns         4387
_refine_ls_number_restraints     1
_refine_ls_R_factor_gt           0.0418
_refine_ls_shift/su_max          0.033
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1222
_reflns_number_gt                3244
_reflns_number_total             4387
_reflns_threshold_expression     F>2.0\s(F)
_cod_data_source_file            jo6b00728_si_002.cif
_cod_data_source_block           VKS-DBJ-OME-EP-DI
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