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_1542678
_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         'C19 H18 O4'
_chemical_formula_sum            'C19 H18 O4'
_chemical_formula_weight         310.33
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_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                 101.174(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.4895(18)
_cell_length_b                   8.7747(17)
_cell_length_c                   19.062(4)
_cell_measurement_reflns_used    8590
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      35.77
_cell_measurement_theta_min      2.56
_cell_volume                     1557.2(5)
_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 0.999
_diffrn_measured_fraction_theta_max 0.999
_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  0.0375
_diffrn_reflns_av_sigmaI/netI    0.0263
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            15480
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         2.18
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_T_max  0.9710
_exptl_absorpt_correction_T_min  0.2357
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS,(BRUKER,2006)
_exptl_crystal_colour            COLOURLESS
_exptl_crystal_density_diffrn    1.324
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       BLOCK
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.166
_refine_diff_density_min         -0.207
_refine_diff_density_rms         0.040
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     211
_refine_ls_number_reflns         2749
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.0431
_refine_ls_R_factor_gt           0.0375
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0521P)^2^+0.4343P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0993
_refine_ls_wR_factor_ref         0.1042
_reflns_number_gt                2397
_reflns_number_total             2749
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol5b03707_si_005.cif
_cod_data_source_block           atulramana_0m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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_sg_symbol_H-M      'P2(1)/c  '
_cod_database_code               1542678