Unusual formal [4 + 2] cycloaddition of ethyl allenoate with arylidenoxindoles: synthesis of dihydropyran-fused indoles.
Chen, Xiang-Yu; Wen, Ming-Wei; Ye, Song; Wang, Zhi-Xiang; Organic letters 13 (2011) 1138–1141; doi:10.1021/ol103165y

data_1501976
_publ_section_title
;
 Unusual formal [4 + 2] cycloaddition of ethyl allenoate with
 arylidenoxindoles: synthesis of dihydropyran-fused indoles.
;
_journal_issue                   5
_journal_name_full               'Organic letters'
_journal_page_first              1138
_journal_page_last               1141
_journal_paper_doi               10.1021/ol103165y
_journal_volume                  13
_journal_year                    2011
_chemical_formula_moiety         'C24 H23 N O5'
_chemical_formula_sum            'C24 H23 N O5'
_chemical_formula_weight         405.43
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_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                 100.57(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.145(2)
_cell_length_b                   9.4248(19)
_cell_length_c                   21.513(4)
_cell_measurement_reflns_used    6103
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      27.4745
_cell_measurement_theta_min      1.9260
_cell_volume                     2022.1(7)
_computing_cell_refinement       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_collection       'CrystalClear (Rigaku Inc., 2008)'
_computing_data_reduction        'CrystalClear (Rigaku Inc., 2008)'
_computing_molecular_graphics
;
 Mercury: visualization and analysis of crystal structures, C. F. Macrae,
 P. R. Edgington, P. McCabe, E. Pidcock, G. P. Shields, R. Taylor,
 M. Towler and J. van de Streek, J. Appl. Cryst., 39, 453-457, 2006.
;
_computing_publication_material  'SHELX-97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_detector_area_resol_mean 28.5714
_diffrn_measured_fraction_theta_full 0.976
_diffrn_measured_fraction_theta_max 0.976
_diffrn_measurement_device_type  'Saturn724+ CCD'
_diffrn_measurement_method       '\w scans at fixed \c = 45\%'
_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  0.0307
_diffrn_reflns_av_sigmaI/netI    0.0386
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            6583
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.93
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.4860
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'CrystalClear (Rigaku Inc., 2008)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.332
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             856
_exptl_crystal_size_max          0.60
_exptl_crystal_size_mid          0.50
_exptl_crystal_size_min          0.40
_refine_diff_density_max         0.312
_refine_diff_density_min         -0.318
_refine_diff_density_rms         0.124
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.211
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     271
_refine_ls_number_reflns         3479
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.211
_refine_ls_R_factor_all          0.0621
_refine_ls_R_factor_gt           0.0531
_refine_ls_shift/su_max          0.009
_refine_ls_shift/su_mean         0.002
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0637P)^2^+0.7843P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1374
_refine_ls_wR_factor_ref         0.1504
_reflns_number_gt                3235
_reflns_number_total             3479
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol103165y_si_002.cif
_cod_data_source_block           a
_cod_original_cell_volume        2022.0(7)
_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               1501976