Novel formation and use of a Nicholas carbocation in the synthesis of highly substituted tetrahydrofurans.
Christie, Steven D. R.; Davoile, Ryan J.; Elsegood, Mark R. J.; Fryatt, Ross; Jones, Raymond C. F.; Pritchard, Gareth J.; Chemical communications (Cambridge, England)  (2004) 2474–2475; doi:10.1039/b411367e

data_7113381
_publ_section_title
;
 Novel formation and use of a Nicholas carbocation in the synthesis of
 highly substituted tetrahydrofurans.
;
_journal_issue                   21
_journal_name_full
'Chemical communications (Cambridge, England)'
_journal_page_first              2474
_journal_page_last               2475
_journal_paper_doi               10.1039/b411367e
_journal_year                    2004
_chemical_formula_sum            'C22 H15 Co2 N O13'
_chemical_formula_weight         619.21
_chemical_name_systematic
;
?
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                83.215(4)
_cell_angle_beta                 86.122(4)
_cell_angle_gamma                67.370(4)
_cell_formula_units_Z            2
_cell_length_a                   6.8834(15)
_cell_length_b                   8.1890(18)
_cell_length_c                   23.757(5)
_cell_measurement_reflns_used    10608
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      53.79
_cell_measurement_theta_min      5.18
_cell_volume                     1227.0(5)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL and local programs'
_computing_structure_refinement  'Bruker SHELXTL'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'Bruker SMART 1000 CCD diffractometer'
_diffrn_measurement_method       '\w rotation with narrow frames'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0586
_diffrn_reflns_av_sigmaI/netI    0.0946
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            7010
_diffrn_reflns_theta_full        22.50
_diffrn_reflns_theta_max         22.50
_diffrn_reflns_theta_min         1.73
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.422
_exptl_absorpt_correction_T_max  0.972
_exptl_absorpt_correction_T_min  0.644
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS, v.2.08, Sheldrick, G.M., (2003)'
_exptl_crystal_colour            'dark red'
_exptl_crystal_density_diffrn    1.676
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             624
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.769
_refine_diff_density_min         -0.754
_refine_diff_density_rms         0.129
_refine_ls_extinction_coef       0.0037(10)
_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   1.101
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     349
_refine_ls_number_reflns         3195
_refine_ls_number_restraints     14
_refine_ls_restrained_S_all      1.100
_refine_ls_R_factor_all          0.1132
_refine_ls_R_factor_gt           0.0769
_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^)+(0.0258P)^2^+13.7646P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1549
_refine_ls_wR_factor_ref         0.1681
_reflns_number_gt                2122
_reflns_number_total             3195
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            b411367e.txt
_cod_data_source_block           trans2c
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               7113381