Synthesis of chiral hexacyclic steroids via [8π + 2π] cycloaddition of diazafulvenium methides.
Lopes, Susana M. M.; Correia, Cátia F O; Nunes, Sandra C. C.; Pereira, Nelson A. M.; Ferreira, Ana R. F.; Sousa, Emanuel P.; Gomes, Clara S. B.; Salvador, Jorge A. R.; Pais, Alberto A. C. C.; Pinho E Melo, Teresa M V D; Organic & biomolecular chemistry 13 (2015) 9127–9139; doi:10.1039/c5ob01110h

data_7154607
_publ_section_title
;
 Synthesis of chiral hexacyclic steroids via [8\p + 2\p] cycloaddition of
 diazafulvenium methides.
;
_journal_issue                   34
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              9127
_journal_page_last               9139
_journal_paper_doi               10.1039/c5ob01110h
_journal_volume                  13
_journal_year                    2015
_chemical_formula_moiety         'C26 H23 N3 O6'
_chemical_formula_sum            'C26 H23 N3 O6'
_chemical_formula_weight         473.47
_chemical_name_systematic
;
(4aR,7aR,8aR)-Dimethyl 8-benzyl-5,7-dioxo-6-phenyl-4a,5,6,7,7a,8-hexahydro-1H,3H-pyrazolo[1,5-a]pyrrolo[3,4-d]pyridine-2,3-dicarboxylate
;
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_audit_update_record
;
2015-06-03 deposited with the CCDC.
2015-07-20 downloaded from the CCDC.
;
_cell_angle_alpha                98.060(6)
_cell_angle_beta                 99.289(7)
_cell_angle_gamma                115.517(6)
_cell_formula_units_Z            4
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_cell_length_b                   14.5445(19)
_cell_length_c                   14.594(2)
_cell_measurement_reflns_used    1801
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      20.23
_cell_measurement_theta_min      2.40
_cell_volume                     2352.7(6)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    ORTEP
_computing_publication_material  enCIFer
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    SIR2014
_diffrn_ambient_temperature      150(2)
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_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1036
_diffrn_reflns_av_unetI/netI     0.1663
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.990
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            25820
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.990
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         25.909
_diffrn_reflns_theta_min         1.596
_diffrn_source                   'sealed tube'
_exptl_absorpt_coefficient_mu    0.096
_exptl_absorpt_correction_T_max  0.990
_exptl_absorpt_correction_T_min  0.962
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1996)'
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.337
_exptl_crystal_description       Plate
_exptl_crystal_F_000             992
_exptl_crystal_size_max          0.400
_exptl_crystal_size_mid          0.200
_exptl_crystal_size_min          0.100
_refine_diff_density_max         0.377
_refine_diff_density_min         -0.321
_refine_diff_density_rms         0.063
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.872
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     635
_refine_ls_number_reflns         9063
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.872
_refine_ls_R_factor_all          0.1744
_refine_ls_R_factor_gt           0.0614
_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^)+(0.0645P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1206
_refine_ls_wR_factor_ref         0.1581
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4179
_reflns_number_total             9063
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c5ob01110h2.cif
_cod_data_source_block           41
_cod_depositor_comments
'Adding full bibliography for 7154606--7154607.cif.'
_cod_original_cell_volume        2352.8(6)
_cod_database_code               7154607
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.962
_shelx_estimated_absorpt_t_max   0.990
_shelx_res_checksum              6671