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_4029079
_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_absolute_configuration ad
_chemical_formula_sum            'C21 H30 N2 O4'
_chemical_formula_weight         374.47
_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                   9.9069(9)
_cell_length_b                   10.5077(9)
_cell_length_c                   20.4388(19)
_cell_measurement_reflns_used    1981
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      41.433
_cell_measurement_theta_min      4.359
_cell_volume                     2127.7(3)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_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      293(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_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  0.0388
_diffrn_reflns_av_sigmaI/netI    0.0444
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            12999
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         26.00
_diffrn_reflns_theta_min         1.99
_exptl_absorpt_coefficient_mu    0.081
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.79846
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.169
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             808
_exptl_crystal_size_max          0.169
_exptl_crystal_size_mid          0.135
_exptl_crystal_size_min          0.035
_refine_diff_density_max         0.128
_refine_diff_density_min         -0.125
_refine_diff_density_rms         0.027
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.8(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.011
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     255
_refine_ls_number_reflns         4175
_refine_ls_number_restraints     18
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0743
_refine_ls_R_factor_gt           0.0459
_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^)+(0.0457P)^2^+0.0539P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0912
_refine_ls_wR_factor_ref         0.1018
_reflns_number_gt                2979
_reflns_number_total             4175
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo402419h_si_005.cif
_cod_data_source_block           cd211518
_cod_depositor_comments
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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      P2(1)2(1)2(1)
_cod_database_code               4029079