Divergent total synthesis of the Lycopodium alkaloids huperzine A, huperzine B, and huperzine U.
Ding, Rui; Fu, Jian-Guo; Xu, Guang-Qiang; Sun, Bing-Feng; Lin, Guo-Qiang; The Journal of organic chemistry 79 (2014) 240–250; doi:10.1021/jo402419h

data_4029075
_publ_section_title
;
 Divergent total synthesis of the Lycopodium alkaloids huperzine A,
 huperzine B, and huperzine U.
;
_journal_issue                   1
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              240
_journal_page_last               250
_journal_paper_doi               10.1021/jo402419h
_journal_volume                  79
_journal_year                    2014
_chemical_formula_sum            'C24 H32 N2 O6'
_chemical_formula_weight         444.52
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_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            8
_cell_length_a                   13.4267(2)
_cell_length_b                   17.8534(3)
_cell_length_c                   20.7231(3)
_cell_measurement_reflns_used    9878
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      67.54
_cell_measurement_theta_min      2.47
_cell_volume                     4967.58(13)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_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      296(2)
_diffrn_measured_fraction_theta_full 0.972
_diffrn_measured_fraction_theta_max 0.972
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0422
_diffrn_reflns_av_sigmaI/netI    0.0397
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            22124
_diffrn_reflns_theta_full        65.00
_diffrn_reflns_theta_max         65.00
_diffrn_reflns_theta_min         4.27
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.700
_exptl_absorpt_correction_T_max  0.8726
_exptl_absorpt_correction_T_min  0.8174
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.189
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1904
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.25
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.278
_refine_diff_density_min         -0.287
_refine_diff_density_rms         0.057
_refine_ls_extinction_coef       0.00076(15)
_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   1.029
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     298
_refine_ls_number_reflns         4104
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.029
_refine_ls_R_factor_all          0.0552
_refine_ls_R_factor_gt           0.0526
_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^)+(0.1018P)^2^+0.9985P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1587
_refine_ls_wR_factor_ref         0.1627
_reflns_number_gt                3779
_reflns_number_total             4104
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo402419h_si_003.cif
_cod_data_source_block           cu_dc1193_0m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/usr/data/users/saulius/automatic-downloads/current/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2281 2013-09-26 08:29:07Z andrius 
;
_cod_original_sg_symbol_H-M      Pbca
_cod_database_code               4029075