Photoinduced [2+2] cycloadditions (the Paterno–Büchi reaction) of 1-acetylisatin with enol ethers—regioselectivity, diastereoselectivity and acid catalysed transformations of the spirooxetane products
Zhang, Yan; Xue, Jie; Gao, Yi; Fun, Hoong-Kun; Xu, Jian-Hua; Journal of the Chemical Society, Perkin Transactions 1  (2002) 345–353; doi:10.1039/b109697d

data_7204301
_publ_section_title
;
 Photoinduced [2+2] cycloadditions (the Paterno--B\"uchi reaction) of
 1-acetylisatin with enol ethers---regioselectivity, diastereoselectivity
 and acid catalysed transformations of the spirooxetane products
;
_journal_coden_ASTM              JCSPCE
_journal_issue                   3
_journal_name_full
'Journal of the Chemical Society, Perkin Transactions 1'
_journal_page_first              345
_journal_page_last               353
_journal_paper_doi               10.1039/b109697d
_journal_year                    2002
_chemical_formula_sum            'C24 H18 N2 O7'
_chemical_formula_weight         446.40
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 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                 98.030(1)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   9.0926(4)
_cell_length_b                   9.1306(4)
_cell_length_c                   12.1838(5)
_cell_measurement_reflns_used    4626
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28.30
_cell_measurement_theta_min      1.69
_cell_volume                     1001.59(7)
_computing_cell_refinement       'SAINT (Siemens, 1996)'
_computing_data_collection       'SMART (Siemens, 1996)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    SHELXTL
_computing_publication_material
;
SHELXTL, PARST (Nardelli, 1995) and PLATON (Spek, 1990)
;
_computing_structure_refinement  SHELXTL
_computing_structure_solution    'SHELXTL (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 0.976
_diffrn_measured_fraction_theta_max 0.976
_diffrn_measurement_device_type
;
Siemens SMART CCD area detector diffractometer
;
_diffrn_measurement_method       '\w 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  0.0831
_diffrn_reflns_av_sigmaI/netI    0.1429
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            7113
_diffrn_reflns_theta_full        28.27
_diffrn_reflns_theta_max         28.27
_diffrn_reflns_theta_min         1.69
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.111
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.480
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             464
_exptl_crystal_size_max          0.48
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.421
_refine_diff_density_min         -0.301
_refine_diff_density_rms         0.094
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   4.4(18)
_refine_ls_extinction_coef       0.049(7)
_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   0.941
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     299
_refine_ls_number_reflns         4463
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.941
_refine_ls_R_factor_all          0.0962
_refine_ls_R_factor_gt           0.0652
_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^)+(0.0923P)^2^+0.0000P] where P==(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1623
_refine_ls_wR_factor_ref         0.2037
_reflns_number_gt                2788
_reflns_number_total             4463
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            b109697d.txt
_cod_data_source_block           compound10
_cod_original_sg_symbol_H-M      P21
_cod_database_code               7204301