Synthesis of maremycins A and D1 via cycloaddition of a nitrone with (E)-3-ethylidene-1-methylindolin-2-one.
Ueda, Tohru; Inada, Mitsuhide; Okamoto, Iwao; Morita, Nobuyoshi; Tamura, Osamu; Organic letters 10 (2008) 2043–2046; doi:10.1021/ol800515w

data_1504660
_publ_section_title
;
 Synthesis of maremycins A and D1 via cycloaddition of a nitrone with
 (E)-3-ethylidene-1-methylindolin-2-one.
;
_journal_issue                   10
_journal_name_full               'Organic letters'
_journal_page_first              2043
_journal_page_last               2046
_journal_paper_doi               10.1021/ol800515w
_journal_volume                  10
_journal_year                    2008
_chemical_absolute_configuration rmad
_chemical_formula_sum            'C21 H20 N2 O4'
_chemical_formula_weight         364.39
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.6455(13)
_cell_length_b                   10.2121(17)
_cell_length_c                   22.500(4)
_cell_measurement_reflns_used    6688
_cell_measurement_temperature    90
_cell_measurement_theta_max      28.03
_cell_measurement_theta_min      2.69
_cell_volume                     1756.7(5)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      90
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.940
_diffrn_measurement_device_type  'CCD area detector'
_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  0.0288
_diffrn_reflns_av_sigmaI/netI    0.0318
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            9751
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.26
_diffrn_reflns_theta_min         1.81
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_T_max  0.9810
_exptl_absorpt_correction_T_min  0.9534
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'SADABS Sheldrick 1996'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.378
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             768
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.262
_refine_diff_density_min         -0.184
_refine_diff_density_rms         0.036
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.0(7)
_refine_ls_extinction_coef       0.0038(9)
_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   1.023
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     247
_refine_ls_number_reflns         3961
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.023
_refine_ls_R_factor_all          0.0306
_refine_ls_R_factor_gt           0.0295
_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^)+(0.0373P)^2^+0.3616P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0738
_refine_ls_wR_factor_ref         0.0747
_reflns_number_gt                3849
_reflns_number_total             3961
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol800515w-file006.cif
_cod_data_source_block           a0702021kka
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               1504660