Transformations of the 2,7-Seco Aspidosperma Alkaloid Leuconolam, Structure Revision of epi-Leuconolam, and Partial Syntheses of Leuconoxine and Leuconodines A and F.
Low, Yun-Yee; Hong, Fong-Jiao; Lim, Kuan-Hon; Thomas, Noel F.; Kam, Toh-Seok; Journal of natural products 77 (2014) 327–338; doi:10.1021/np400922x

data_1513363
_publ_section_title
;
 Transformations of the 2,7-Seco Aspidosperma Alkaloid Leuconolam,
 Structure Revision of epi-Leuconolam, and Partial Syntheses of
 Leuconoxine and Leuconodines A and F.
;
_journal_issue                   2
_journal_name_full               'Journal of natural products'
_journal_page_first              327
_journal_page_last               338
_journal_paper_doi               10.1021/np400922x
_journal_volume                  77
_journal_year                    2014
_chemical_formula_moiety         'C19 H20 N2 O2'
_chemical_formula_sum            'C19 H20 N2 O2'
_chemical_formula_weight         308.37
_chemical_melting_point          439(2)
_chemical_name_common            6,7-dehydroleuconoxine
_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                   8.8855(4)
_cell_length_b                   11.3940(5)
_cell_length_c                   14.8635(7)
_cell_measurement_reflns_used    4675
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      30.24
_cell_measurement_theta_min      2.25
_cell_volume                     1504.80(12)
_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, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.971
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\w 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  0.0000
_diffrn_reflns_av_sigmaI/netI    0.0288
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            2554
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         30.60
_diffrn_reflns_theta_min         2.25
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_T_max  0.9772
_exptl_absorpt_correction_T_min  0.9585
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.361
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.48
_exptl_crystal_size_mid          0.34
_exptl_crystal_size_min          0.26
_refine_diff_density_max         0.286
_refine_diff_density_min         -0.246
_refine_diff_density_rms         0.045
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.039
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     209
_refine_ls_number_reflns         2554
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.039
_refine_ls_R_factor_all          0.0433
_refine_ls_R_factor_gt           0.0374
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         <0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0555P)^2^+0.2387P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0929
_refine_ls_wR_factor_ref         0.0965
_reflns_number_gt                2316
_reflns_number_total             2554
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            np400922x_si_005.cif
_cod_data_source_block           6,7-dehydroleuconoxine
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_melting_point' value '164-168 oC' was changed to '439(2)'
- it was converted from degrees Celsius(C) to Kelvins(K), the average
value was taken and precision was
estimated.

'_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               1513363