Highly diastereoselective entry into chiral spirooxindole-based 4-methyleneazetidines via formal [2+2] annulation reaction.
Rainoldi, G.; Faltracco, M.; Lo Presti, L.; Silvani, A.; Lesma, G.; Chemical communications (Cambridge, England) 52 (2016) 11575–11578; doi:10.1039/c6cc05838h

data_7124954
_publ_section_title
;
 Highly diastereoselective entry into chiral spirooxindole-based
 4-methyleneazetidines via formal [2+2] annulation reaction.
;
_journal_issue                   77
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              11575
_journal_page_last               11578
_journal_paper_doi               10.1039/c6cc05838h
_journal_volume                  52
_journal_year                    2016
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C25 H28 N2 O4 S'
_chemical_formula_sum            'C25 H28 N2 O4 S'
_chemical_formula_weight         452.55
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.4.5
_audit_creation_date             2016-05-25
_audit_creation_method           SHELXL-2014
_audit_update_record
;
2016-06-24 deposited with the CCDC.
2016-08-26 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.78200(10)
_cell_length_b                   10.8274(2)
_cell_length_c                   26.0299(4)
_cell_measurement_reflns_used    9954
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      20.80
_cell_measurement_theta_min      2.5
_cell_volume                     2475.08(7)
_computing_cell_refinement       'SAINT+ (Bruker AXS, Madison (USA) 1994-1996)'
_computing_data_collection       'SAINT+ (Bruker AXS, Madison (USA) 1994-1996)'
_computing_data_reduction        'SAINT+ (Bruker AXS, Madison (USA) 1994-1996)'
_computing_molecular_graphics    'Diamond v3.2i (Brandenburg, 2012)'
_computing_structure_refinement  'SHELXL-2014/4 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-2014/4 (Sheldrick, 2014)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker AXS APEX CCD area-detector'
_diffrn_measurement_method       \w-scan
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_unetI/netI     0.0277
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.996
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       33
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            29165
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.995
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.597
_diffrn_reflns_theta_min         1.565
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.163
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   twinabs
_exptl_crystal_colour            brown
_exptl_crystal_density_diffrn    1.214
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Prism
_exptl_crystal_F_000             960
_exptl_crystal_recrystallization_method 'Re-crystallisation from solvent'
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_exptl_transmission_factor_max   1.000
_exptl_transmission_factor_min   0.973
_refine_diff_density_max         0.209
_refine_diff_density_min         -0.169
_refine_diff_density_rms         0.027
_refine_ls_abs_structure_details
;
 Flack x determined using 1511 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.03(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.056
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     318
_refine_ls_number_reflns         29165
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.056
_refine_ls_R_factor_all          0.0457
_refine_ls_R_factor_gt           0.0350
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0552P)^2^+0.0523P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0946
_refine_ls_wR_factor_ref         0.1013
_reflns_Friedel_coverage         0.759
_reflns_Friedel_fraction_full    1.000
_reflns_Friedel_fraction_max     0.994
_reflns_number_gt                23117
_reflns_number_total             29165
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c6cc05838h2.cif
_cod_data_source_block           sc01s
_cod_original_cell_volume        2475.09(7)
_cod_database_code               7124954
_shelxl_version_number           2014/4
_shelx_res_checksum              32458
_solvent_exptl_crystal_recrystallization_method 'Isopropyl ether'