Cascade [1,3]-Sigmatropic Rearrangements of Ketene O,O-Acetals: Kinetic and DFT Level Mechanistic Studies
Perla Y. López-Camacho; Pedro Joseph-Nathan; Bárbara Gordillo-Román; Oscar R. Suárez-Castillo; Martha S. Morales-Ríos; Journal of Organic Chemistry 75 (2010) 1898–1910; doi:10.1021/jo902520z

data_4025300
_publ_section_title
;
 Cascade [1,3]-Sigmatropic Rearrangements of Ketene O,O-Acetals: Kinetic
 and DFT Level Mechanistic Studies
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              1898
_journal_page_last               1910
_journal_paper_doi               10.1021/jo902520z
_journal_volume                  75
_journal_year                    2010
_chemical_formula_moiety         'C21 H18 N2 O4'
_chemical_formula_sum            'C21 H18 N2 O4'
_chemical_formula_weight         362.37
_chemical_name_systematic
;
1a-Benzyl-1-cyano-1a,6a-dihydro-1H-6-aza-cyclopropa
[alpha]indene-1,6-dicarboxylic acid dimethyl ester.
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 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                 111.248(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.5591(4)
_cell_length_b                   19.9752(7)
_cell_length_c                   10.3978(4)
_cell_measurement_reflns_used    600
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      26.00
_cell_measurement_theta_min      1.99
_cell_volume                     1850.44(12)
_computing_cell_refinement       'Bruker Smart'
_computing_data_collection       'Bruker Smart'
_computing_data_reduction        'Bruker Smart'
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker Smart 6000 CCD'
_diffrn_measurement_method       'Phi and omega scans'
_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  0.0393
_diffrn_reflns_av_sigmaI/netI    0.0464
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       24
_diffrn_reflns_limit_k_min       -22
_diffrn_reflns_limit_l_max       12
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            12483
_diffrn_reflns_theta_full        26.01
_diffrn_reflns_theta_max         26.01
_diffrn_reflns_theta_min         2.04
_diffrn_standards_decay_%        <1
_exptl_absorpt_coefficient_mu    0.091
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.301
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             760
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.29
_exptl_crystal_size_min          0.19
_refine_diff_density_max         0.202
_refine_diff_density_min         -0.225
_refine_diff_density_rms         0.033
_refine_ls_extinction_coef       0.025(2)
_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   0.931
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     245
_refine_ls_number_reflns         3633
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.931
_refine_ls_R_factor_all          0.0748
_refine_ls_R_factor_gt           0.0428
_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^)+(0.0655P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1082
_refine_ls_wR_factor_ref         0.1196
_reflns_number_gt                2276
_reflns_number_total             3633
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo902520z_si_002_2.cif
_cod_data_source_block           3c
_cod_database_code               4025300