Modified chiral triazolium salts for enantioselective benzoin cyclization of enolizable keto-aldehydes: synthesis of (+)-sappanone B.
Takikawa, Hiroshi; Suzuki, Keisuke; Organic letters 9 (2007) 2713–2716; doi:10.1021/ol070929p

data_1505434
_publ_section_title
;
 Modified chiral triazolium salts for enantioselective benzoin cyclization
 of enolizable keto-aldehydes: synthesis of (+)-sappanone B.
;
_journal_issue                   14
_journal_name_full               'Organic letters'
_journal_page_first              2713
_journal_page_last               2716
_journal_paper_doi               10.1021/ol070929p
_journal_volume                  9
_journal_year                    2007
_chemical_formula_moiety         'C21 H24 O5 '
_chemical_formula_sum            'C21 H24 O5'
_chemical_formula_weight         356.42
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.300(1)
_cell_length_b                   13.636(2)
_cell_length_c                   21.235(4)
_cell_measurement_reflns_used    16509
_cell_measurement_temperature    223.2
_cell_measurement_theta_max      68.2
_cell_measurement_theta_min      3.2
_cell_volume                     1824.2(5)
_computing_cell_refinement       PROCESS-AUTO
_computing_data_collection       PROCESS-AUTO
_computing_data_reduction        'teXsan Ver. 1.11'
_computing_publication_material  'teXsan Ver. 1.11'
_computing_structure_refinement  'teXsan Ver. 1.10'
_computing_structure_solution    SIR97
_diffrn_detector_area_resol_mean 10.00
_diffrn_measured_fraction_theta_full 0.9877
_diffrn_measured_fraction_theta_max 0.9877
_diffrn_measurement_device_type  'Rigaku RAXIS-RAPID Imaging Plate'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.5419
_diffrn_reflns_av_R_equivalents  0.042
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            16307
_diffrn_reflns_theta_full        68.24
_diffrn_reflns_theta_max         68.24
_exptl_absorpt_coefficient_mu    0.753
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.298
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       unknown
_exptl_crystal_size_max          0.550
_exptl_crystal_size_mid          0.380
_exptl_crystal_size_min          0.350
_refine_diff_density_max         0.36
_refine_diff_density_min         -0.56
_refine_ls_abs_structure_Flack   1.5(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.877
_refine_ls_hydrogen_treatment    noref
_refine_ls_number_parameters     236
_refine_ls_number_reflns         1878
_refine_ls_R_factor_gt           0.0667
_refine_ls_shift/su_max          0.1446
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^) + (0.05000(Max(Fo^2^,0) + 2Fc^2^)/3)^2^]'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1814
_reflns_number_gt                1858
_reflns_number_total             1926
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
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_cod_data_source_block           takikawa3
_cod_original_cell_volume        1824(2)
_cod_original_sg_symbol_H-M      'P 21 21 21   '
_cod_original_formula_sum        'C21 H24 O5 '
_cod_database_code               1505434