Flexible approach to stemona alkaloids: total syntheses of (-)-stemospironine and three new diastereoisomeric analogs.
Bardají, Nuria; Sánchez-Izquierdo, Francisco; Alibés, Ramón; Font, Josep; Busqué, Félix; Figueredo, Marta; Organic letters 14 (2012) 4854–4857; doi:10.1021/ol302185j

data_1508646
_publ_section_title
;
 Flexible approach to stemona alkaloids: total syntheses of
 (-)-stemospironine and three new diastereoisomeric analogs.
;
_journal_issue                   18
_journal_name_full               'Organic letters'
_journal_page_first              4854
_journal_page_last               4857
_journal_paper_doi               10.1021/ol302185j
_journal_volume                  14
_journal_year                    2012
_chemical_absolute_configuration rm
_chemical_formula_sum            'C19 H27 N O5 S'
_chemical_formula_weight         381.49
_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                   5.927(5)
_cell_length_b                   12.535(5)
_cell_length_c                   24.978(5)
_cell_measurement_temperature    293(2)
_cell_volume                     1855.7(18)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.758
_diffrn_measured_fraction_theta_max 0.758
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.7379
_diffrn_reflns_av_R_equivalents  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0696
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2213
_diffrn_reflns_theta_full        26.35
_diffrn_reflns_theta_max         26.35
_diffrn_reflns_theta_min         2.30
_exptl_absorpt_coefficient_mu    0.205
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   scalepack
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.365
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             776
_exptl_crystal_size_max          0.8
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.323
_refine_diff_density_min         -0.332
_refine_diff_density_rms         0.071
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.5(3)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.083
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     251
_refine_ls_number_reflns         1678
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.083
_refine_ls_R_factor_all          0.1175
_refine_ls_R_factor_gt           0.0638
_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^)+(0.0586P)^2^+3.8215P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1329
_refine_ls_wR_factor_ref         0.1581
_reflns_number_gt                1135
_reflns_number_total             2213
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol302185j_si_002.cif
_cod_data_source_block           shelxl
_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 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_cell_volume        1855.7(20)
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               1508646