Alternative Spiroketalization Methods toward Purpuromycin: A Hemiketal Conjugate Addition Strategy and Use of an Electron-Rich Isocoumarin Precursor
Rakeshwar Bandichhor; Andrew N. Lowell; Marisa C. Kozlowski; Journal of Organic Chemistry 76 (2011) 6475–6487; doi:10.1021/jo200398v

data_4026501
_publ_section_title
;
 Alternative Spiroketalization Methods toward Purpuromycin: A Hemiketal
 Conjugate Addition Strategy and Use of an Electron-Rich Isocoumarin
 Precursor
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              6475
_journal_page_last               6487
_journal_paper_doi               10.1021/jo200398v
_journal_volume                  76
_journal_year                    2011
_chemical_formula_sum            'C18 H22 N2 O9'
_chemical_formula_weight         410.38
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 91.325(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   6.4729(7)
_cell_length_b                   9.5197(10)
_cell_length_c                   30.427(3)
_cell_measurement_temperature    143(1)
_cell_volume                     1874.4(3)
_computing_data_collection       'CrystalClear (Rigaku, 1999)'
_computing_data_reduction        'CrystalClear (Rigaku, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Altomare, 1999)'
_diffrn_ambient_temperature      143(1)
_diffrn_measured_fraction_theta_full 0.819
_diffrn_measured_fraction_theta_max 0.819
_diffrn_measurement_device       'CCD Area Detector'
_diffrn_measurement_device_type  'Rigaku Mercury'
_diffrn_measurement_method       'phi and omega rotations'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'rotating anode'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0180
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            9116
_diffrn_reflns_theta_full        24.05
_diffrn_reflns_theta_max         24.05
_diffrn_reflns_theta_min         2.24
_exptl_absorpt_coefficient_mu    0.118
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.6276
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_density_diffrn    1.454
_exptl_crystal_F_000             864
_exptl_crystal_size_max          0.38
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.607
_refine_diff_density_min         -0.601
_refine_diff_density_rms         0.151
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.213
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     268
_refine_ls_number_reflns         9116
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.213
_refine_ls_R_factor_all          0.0877
_refine_ls_R_factor_gt           0.0762
_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^)+(0.0516P)^2^+7.2702P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1985
_refine_ls_wR_factor_ref         0.2052
_reflns_number_gt                7984
_reflns_number_total             9116
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo200398v_si_002.cif
_cod_data_source_block           shelxl
_cod_original_sg_symbol_H-M      'P 21/n '
_cod_database_code               4026501