An Approach to the Welwistatin Core via a Diazoketone Rearrangement-Ring Expansion Strategy.
Lam, Shuk Mei; Wong, Wing-Tak; Chiu, Pauline; Organic letters 19 (2017) 4468–4471; doi:10.1021/acs.orglett.7b01988

data_1547062
_publ_section_title
;
 An Approach to the Welwistatin Core via a Diazoketone Rearrangement-Ring
 Expansion Strategy.
;
_journal_issue                   17
_journal_name_full               'Organic letters'
_journal_page_first              4468
_journal_page_last               4471
_journal_paper_doi               10.1021/acs.orglett.7b01988
_journal_volume                  19
_journal_year                    2017
_chemical_formula_moiety         'C16 H15 Br O4'
_chemical_formula_sum            'C16 H15 Br O4'
_chemical_formula_weight         351.19
_space_group_IT_number           56
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      56
_symmetry_space_group_name_Hall  '-P 2ab 2ac'
_symmetry_space_group_name_H-M   'P c c n'
_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            8
_cell_length_a                   15.6419(12)
_cell_length_b                   23.9707(18)
_cell_length_c                   7.8208(6)
_cell_measurement_reflns_used    15145
_cell_measurement_temperature    301(2)
_cell_measurement_theta_max      25.03
_cell_measurement_theta_min      2.60
_cell_volume                     2932.4(4)
_computing_cell_refinement       'SAINT (Bruker AXS Inc, 2006)'
_computing_data_collection       'SMART (Bruker AXS Inc, 1998)'
_computing_data_reduction        'SHELXL-97 (Sheldrick, 2008)'
_computing_molecular_graphics    'MERCURY (Macrae et al., 2008)'
_computing_publication_material  'SHELXL97 (Sheldrick, 2008)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      301(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker SMART 1000 CCD'
_diffrn_measurement_method       '\w & \f 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  0.0217
_diffrn_reflns_av_sigmaI/netI    0.0148
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       27
_diffrn_reflns_limit_k_min       -28
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            15145
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         2.60
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.816
_exptl_absorpt_correction_T_max  0.6311
_exptl_absorpt_correction_T_min  0.3574
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2004)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.591
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1424
_exptl_crystal_size_max          0.46
_exptl_crystal_size_mid          0.19
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.405
_refine_diff_density_min         -0.425
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.043
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     211
_refine_ls_number_reflns         2585
_refine_ls_number_restraints     15
_refine_ls_restrained_S_all      1.050
_refine_ls_R_factor_all          0.0379
_refine_ls_R_factor_gt           0.0304
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0442P)^2^+1.3176P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0772
_refine_ls_wR_factor_ref         0.0810
_reflns_number_gt                2182
_reflns_number_total             2585
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ol7b01988_si_004.cif
_cod_data_source_block           shelxl
_cod_database_code               1547062