Application of the Helquist Annulation in Lycopodium Alkaloid Synthesis: Unified Total Syntheses of (-)-8-Deoxyserratinine, (+)-Fawcettimine, and (+)-Lycoflexine
Yu-Rong Yang; Liang Shen; Jiu-Zhong Huang; Tao Xu; Kun Wei; Journal of Organic Chemistry 76 (2011) 3684–3690; doi:10.1021/jo1023188

data_4026276
_publ_section_title
;
 Application of the Helquist Annulation in Lycopodium Alkaloid Synthesis:
 Unified Total Syntheses of (-)-8-Deoxyserratinine, (+)-Fawcettimine, and
 (+)-Lycoflexine
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              3684
_journal_page_last               3690
_journal_paper_doi               10.1021/jo1023188
_journal_volume                  76
_journal_year                    2011
_chemical_formula_sum            'C21 H35 N O5'
_chemical_formula_weight         381.50
_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                   7.817(6)
_cell_length_b                   8.455(7)
_cell_length_c                   33.54(3)
_cell_measurement_reflns_used    1268
_cell_measurement_temperature    273(2)
_cell_measurement_theta_max      17.12
_cell_measurement_theta_min      2.43
_cell_volume                     2217(3)
_computing_cell_refinement       'Bruker APEX-II'
_computing_data_collection       'Bruker APEX-II'
_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      273(2)
_diffrn_measured_fraction_theta_full 0.930
_diffrn_measured_fraction_theta_max 0.930
_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  0.1053
_diffrn_reflns_av_sigmaI/netI    0.2294
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       42
_diffrn_reflns_limit_l_min       -44
_diffrn_reflns_number            14897
_diffrn_reflns_theta_full        28.72
_diffrn_reflns_theta_max         28.72
_diffrn_reflns_theta_min         2.43
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_T_max  0.9654
_exptl_absorpt_correction_T_min  0.9231
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.143
_exptl_crystal_description       prism
_exptl_crystal_F_000             832
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.17
_refine_diff_density_max         0.312
_refine_diff_density_min         -0.234
_refine_diff_density_rms         0.089
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -2(3)
_refine_ls_extinction_coef       0.118(12)
_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   0.963
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     251
_refine_ls_number_reflns         5170
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.963
_refine_ls_R_factor_all          0.2221
_refine_ls_R_factor_gt           0.0891
_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^)+(0.0427P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2026
_refine_ls_wR_factor_ref         0.2790
_reflns_number_gt                1888
_reflns_number_total             5170
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo1023188_si_003.cif
_cod_data_source_block           100426c_0m
_cod_database_code               4026276