Cascade Polycyclization: Exploration of a Convergent Route to Access Various Tricyclic and Tetracyclic Products Related to Sterols
Benoit Guay; Pierre Deslongchamps; Journal of Organic Chemistry 68 (2003) 6140–6148; doi:10.1021/jo034280n

data_4022434
_publ_section_title
;
 Cascade Polycyclization: Exploration of a Convergent Route
 to Access Various Tricyclic and Tetracyclic Products
 Related to Sterols
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              6140
_journal_page_last               6148
_journal_paper_doi               10.1021/jo034280n
_journal_volume                  68
_journal_year                    2003
_chemical_formula_sum            'C21 H26 O7'
_chemical_formula_weight         390.42
_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                   6.6967(17)
_cell_length_b                   12.147(3)
_cell_length_c                   23.158(3)
_cell_measurement_temperature    293(2)
_cell_volume                     1883.8(6)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.991
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0341
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            1855
_diffrn_reflns_theta_full        64.98
_diffrn_reflns_theta_max         64.98
_diffrn_reflns_theta_min         5.28
_exptl_absorpt_coefficient_mu    0.856
_exptl_crystal_density_diffrn    1.377
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             832
_refine_diff_density_max         0.168
_refine_diff_density_min         -0.178
_refine_diff_density_rms         0.042
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.2(4)
_refine_ls_extinction_coef       0.0067(10)
_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   1.044
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     254
_refine_ls_number_reflns         1855
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.044
_refine_ls_R_factor_all          0.0552
_refine_ls_R_factor_gt           0.0486
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0705P)^2^+0.6122P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1252
_refine_ls_wR_factor_ref         0.1299
_reflns_number_gt                1644
_reflns_number_total             1855
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo034280nsi20030611_112520_7.cif
_cod_data_source_block           ben1553
_cod_database_code               4022434