Reversibility in the boron-mediated ketone-ketone aldol reaction.
Cergol, Katie M; Jensen, Paul; Turner, Peter; Coster, Mark J; Chemical communications (Cambridge, England)  (2007) 1363–1365; doi:10.1039/b617094c

data_7101810
_publ_section_title
;
 Reversibility in the boron-mediated ketone-ketone aldol reaction.
;
_journal_issue                   13
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              1363
_journal_page_last               1365
_journal_paper_doi               10.1039/b617094c
_journal_year                    2007
_chemical_formula_moiety         'C20 H36 O2'
_chemical_formula_sum            'C20 H36 O2'
_chemical_formula_weight         308.49
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 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                 104.982(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   13.179(1)
_cell_length_b                   12.282(1)
_cell_length_c                   12.063(1)
_cell_measurement_reflns_used    8700
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      28.2726
_cell_measurement_theta_min      2.3041
_cell_volume                     1886.2(3)
_computing_cell_refinement       'SAINT Ver. 6.45 (Bruker-AXS, 2003)'
_computing_data_collection       'SMART Ver. 5.054 (Bruker-AXS, 1998)'
_computing_data_reduction        'SAINT Ver. 6.45'
_computing_molecular_graphics    'SHELXTL Ver. 6.14 (Bruker-AXS, 2003)'
_computing_publication_material  'modiCIFer-12162005 (Guzei, 2005)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_crystal_treatment
;
attached with Exxon Paratone N, to a short length
of fibre supported on a thin piece of copper wire
inserted in a copper mounting pin. The crystal was
quenched in a cold nitrogen gas stream from an
Oxford Cryosystems Cryostream.
;
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.954
_diffrn_measurement_device_type  'Bruker CCD-1000 area detector'
_diffrn_measurement_method       \w
_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  0.0203
_diffrn_reflns_av_sigmaI/netI    0.0172
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            18394
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         28.32
_diffrn_reflns_theta_min         2.30
_diffrn_standards_decay_%        0.35
_diffrn_standards_number         207
_exptl_absorpt_coefficient_mu    0.067
_exptl_absorpt_correction_T_max  0.972
_exptl_absorpt_correction_T_min  0.928
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS (Bruker-AXS, 2004)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.086
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             688
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.45
_exptl_crystal_size_min          0.43
_refine_diff_density_max         0.367
_refine_diff_density_min         -0.165
_refine_diff_density_rms         0.037
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.041
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     208
_refine_ls_number_reflns         4483
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.0515
_refine_ls_R_factor_gt           0.0411
_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^)+(0.0686P)^2^+0.3458P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1114
_refine_ls_wR_factor_ref         0.1230
_reflns_number_gt                3692
_reflns_number_total             4483
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            b617094c.txt
_cod_data_source_block           mc06pj4
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_Hall     '-P 2ybc '
_cod_original_sg_symbol_H-M      'P 1 21/c 1 '
_cod_database_code               7101810