A Biosynthetic Proposal for Ring Formation in the Antitumor Agent Halichomycin. Asymmetric Synthesis of the AB-Carbon Backbone of Halichomycin
Hale, Karl J.; Dimopoulos, Paschalis; Cheung, Maxine L. F.; Frigerio, Mark; Steed, Jonathan W.; Levett, Philip C.; Organic Letters 4 (2002) 897–900; doi:10.1021/ol017266a

data_1507437
_publ_section_title
;
 A Biosynthetic Proposal for Ring Formation in the Antitumor Agent
 Halichomycin. Asymmetric Synthesis of the AB-Carbon Backbone of
 Halichomycin
;
_journal_coden_ASTM              ORLEF7
_journal_issue                   6
_journal_name_full               'Organic Letters'
_journal_page_first              897
_journal_page_last               900
_journal_paper_doi               10.1021/ol017266a
_journal_volume                  4
_journal_year                    2002
_chemical_formula_sum            'C45 H72 I N O7 Si2'
_chemical_formula_weight         922.13
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
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_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
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 107.130(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   14.6699(5)
_cell_length_b                   7.7774(3)
_cell_length_c                   21.9785(8)
_cell_measurement_temperature    110(2)
_cell_volume                     2396.37(16)
_computing_cell_refinement       DENZO-SMN
_computing_data_collection       Collect
_computing_data_reduction        DENZO-SMN
_computing_molecular_graphics    'Xseed (Barbour, 1999)''
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      110(2)
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       '1o phi & omega frames'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
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_diffrn_reflns_limit_h_max       17
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_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         2.78
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.764
_exptl_absorpt_correction_T_max  0.9628
_exptl_absorpt_correction_T_min  0.7011
_exptl_absorpt_correction_type   scalepack
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.278
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             972
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.05
_exptl_crystal_size_min          0.05
_refine_diff_density_max         1.992
_refine_diff_density_min         -1.000
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_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.06(2)
_refine_ls_extinction_coef       0.0011(4)
_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   1.154
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     520
_refine_ls_number_reflns         8240
_refine_ls_number_restraints     13
_refine_ls_restrained_S_all      1.154
_refine_ls_R_factor_all          0.1218
_refine_ls_R_factor_gt           0.0921
_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^)+(0.0000P)^2^+3.4655P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1143
_refine_ls_wR_factor_ref         0.1227
_reflns_number_gt                6577
_reflns_number_total             8240
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol017266a_s1.cif
_cod_data_source_block           pd146m
_cod_depositor_comments
;
 Updated bibliographic information.

 Antanas Vaitkus,
 2019-09-22
;
_cod_original_cell_volume        2396.37(15)
_cod_original_sg_symbol_H-M      P21
_cod_original_formula_sum        'C22.50 H36 I0.50 N0.50 O3.50 Si'
_cod_database_code               1507437