Stereoselective synthesis of spirocyclopentanones via N-heterocyclic carbene-catalyzed reactions of enals and dienones
Nair, Vijay; Babu, Beneesh Pattoorpadi; Vellalath, Sreekumar; Suresh, Eringathodi; Chemical Communications (Cambridge, United Kingdom)  (2008) 747–749; doi:10.1039/b715733a

data_7113126
_publ_section_title
;
 Stereoselective synthesis of spirocyclopentanones via N-heterocyclic
 carbene-catalyzed reactions of enals and dienones
;
_journal_coden_ASTM              CHCOFS
_journal_issue                   6
_journal_name_full
;
 Chemical Communications (Cambridge, United Kingdom)
;
_journal_page_first              747
_journal_page_last               749
_journal_paper_doi               10.1039/b715733a
_journal_year                    2008
_chemical_formula_sum            'C30 H28 O4'
_chemical_formula_weight         452.52
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 96.239(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   43.220(18)
_cell_length_b                   6.205(3)
_cell_length_c                   17.784(7)
_cell_measurement_temperature    293(2)
_cell_volume                     4741(4)
_computing_cell_refinement       'BRUKER SMART'
_computing_data_collection       'BRUKER SMART'
_computing_data_reduction        'BRUKER SAINT'
_computing_molecular_graphics    ORTEP
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'BRUKER SMART APEX CCD DIFFRACTOMETER'
_diffrn_measurement_method       'OMEGA-PHI 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  0.1007
_diffrn_reflns_av_sigmaI/netI    0.1266
_diffrn_reflns_limit_h_max       48
_diffrn_reflns_limit_h_min       -50
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            11325
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.90
_exptl_absorpt_coefficient_mu    0.083
_exptl_absorpt_correction_T_max  0.9934
_exptl_absorpt_correction_T_min  0.9620
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'BRUKER SADABS'
_exptl_crystal_colour            colurless
_exptl_crystal_density_diffrn    1.268
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plates
_exptl_crystal_F_000             1920
_exptl_crystal_size_max          0.47
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.239
_refine_diff_density_min         -0.216
_refine_diff_density_rms         0.055
_refine_ls_extinction_coef       0.0014(3)
_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   1.097
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     310
_refine_ls_number_reflns         4166
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.097
_refine_ls_R_factor_all          0.1775
_refine_ls_R_factor_gt           0.0966
_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^)+(0.0726P)^2^+1.7574P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1833
_refine_ls_wR_factor_ref         0.2157
_reflns_number_gt                2262
_reflns_number_total             4166
_reflns_threshold_expression     >2sigma(I)
_cod_duplicate_entry             7102878
_cod_data_source_file            b715733a.txt
_cod_data_source_block           iiipbb1m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/automatic-downloads/retrospective/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from
2011-04-26.

'_exptl_absorpt_correction_type' value 'MULTI-SCAN'
changed to 'multi-scan' according to
/usr/data/users/saulius/automatic-downloads/retrospective/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               7113126