o-Quinone Methides via Oxone-Mediated Benzofuran Oxidative Dearomatization and Their Intramolecular Cycloaddition with Carbonyl Groups: An Expeditious Construction of the Central Tetracyclic Core of Integrastatins, Epicoccolide A, and Epicocconigrone A.
More, Atul A.; Ramana, Chepuri V.; Organic letters 18 (2016) 612–615; doi:10.1021/acs.orglett.5b03707

data_1542680
_publ_section_title
;
 o-Quinone Methides via Oxone-Mediated Benzofuran Oxidative
 Dearomatization and Their Intramolecular Cycloaddition with Carbonyl
 Groups: An Expeditious Construction of the Central Tetracyclic Core of
 Integrastatins, Epicoccolide A, and Epicocconigrone A.
;
_journal_issue                   3
_journal_name_full               'Organic letters'
_journal_page_first              612
_journal_page_last               615
_journal_paper_doi               10.1021/acs.orglett.5b03707
_journal_volume                  18
_journal_year                    2016
_chemical_formula_moiety         'C16 H12 O3'
_chemical_formula_sum            'C16 H12 O3'
_chemical_formula_weight         252.25
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            16
_cell_length_a                   10.0417(11)
_cell_length_b                   18.527(2)
_cell_length_c                   26.755(3)
_cell_measurement_reflns_used    7685
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      21.46
_cell_measurement_theta_min      2.33
_cell_volume                     4977.6(9)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1071
_diffrn_reflns_av_sigmaI/netI    0.0418
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            64616
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.52
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  0.9817
_exptl_absorpt_correction_T_min  0.9656
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS(BRUKER,2006)
_exptl_crystal_colour            COLOURLESS
_exptl_crystal_density_diffrn    1.346
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       BLOCK
_exptl_crystal_F_000             2112
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.251
_refine_diff_density_min         -0.196
_refine_diff_density_rms         0.046
_refine_ls_extinction_coef       0.0009(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.312
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     346
_refine_ls_number_reflns         4378
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.312
_refine_ls_R_factor_all          0.1117
_refine_ls_R_factor_gt           0.0973
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0318P)^2^+6.0654P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1673
_refine_ls_wR_factor_ref         0.1734
_reflns_number_gt                3816
_reflns_number_total             4378
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol5b03707_si_003.cif
_cod_data_source_block           atul5715_0m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/crontab/automatic-downloads/current/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

'_exptl_absorpt_correction_type' value 'MULTI-SCAN' changed to
'multi-scan' according to
/usr/data/users/saulius/crontab/automatic-downloads/current/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

'_refine_ls_hydrogen_treatment' value 'CONSTR' changed to 'constr'
according to
/usr/data/users/saulius/crontab/automatic-downloads/current/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 4268 2015-11-12 08:31:59Z antanas 
;
_cod_original_cell_volume        4977.6(10)
_cod_original_sg_symbol_H-M      'Pbca '
_cod_database_code               1542680