Oppolzer Sultam Directed Aldol as a Key Step for the Stereoselective Syntheses of Antitumor Antibiotic Belactosin C and Its Synthetic Congeners
Gullapalli Kumaraswamy; Mogilisetti Padmaja; Bekkam Markondaiah; Nivedita Jena; Balasubramanian Sridhar; Marelli Udaya Kiran; Journal of Organic Chemistry 71 (2006) 337–340; doi:10.1021/jo0516887

data_4021350
_publ_section_title
;
 Oppolzer Sultam Directed Aldol as a Key Step for the
 Stereoselective Syntheses of Antitumor Antibiotic Belactosin C
 and Its Synthetic Congeners
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              337
_journal_page_last               340
_journal_paper_doi               10.1021/jo0516887
_journal_volume                  71
_journal_year                    2006
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C31 H51 N O5 S Si'
_chemical_formula_sum            'C31 H51 N O5 S Si'
_chemical_formula_weight         577.88
_chemical_name_systematic
; 
N-[(2S,3S methyl), 2-[2'-benzyloxy-1'R-tert-butyl
silyloxyl)ethyl]pentanoyl] borane-10,2-sultam 
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_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                 97.593(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   7.9161(7)
_cell_length_b                   14.7653(13)
_cell_length_c                   14.1615(13)
_cell_measurement_reflns_used    4286
_cell_measurement_temperature    273(2)
_cell_measurement_theta_max      27.00
_cell_measurement_theta_min      2.60
_cell_volume                     1640.7(3)
_computing_cell_refinement       'SAINT (Bruker, 2001)'
_computing_data_collection       'SMART (Bruker, 2001)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'SHELXTL/PC (Sheldrick, 1990)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      273(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.941
_diffrn_measurement_device       'Bruker SMART APEX CCD area-detector'
_diffrn_measurement_device_type  'CCD Area Detector'
_diffrn_measurement_method       '\w scan'
_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  0.0204
_diffrn_reflns_av_sigmaI/netI    0.0361
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -18
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            10003
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.01
_diffrn_reflns_theta_min         2.00
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.172
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.170
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             628
_exptl_crystal_size_max          0.19
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.09
_refine_diff_density_max         0.344
_refine_diff_density_min         -0.165
_refine_diff_density_rms         0.048
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.04(6)
_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     361
_refine_ls_number_reflns         7076
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.043
_refine_ls_R_factor_all          0.0523
_refine_ls_R_factor_gt           0.0469
_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^)+(0.0705P)^2^+0.0061P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1108
_refine_ls_wR_factor_ref         0.1149
_reflns_number_gt                6408
_reflns_number_total             7076
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            jo0516887si20050810_073404_1.cif
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4021350