Hybrid Peptides: Direct Transformation of α/α, β-Unsaturated γ-Hybrid Peptides to α/γ-Hybrid Peptide 12-Helices.
Bandyopadhyay, Anupam; Gopi, Hosahudya N.; Organic letters 14 (2012) 2770–2773; doi:10.1021/ol300987d

data_1507725
_publ_section_title
;
 Hybrid Peptides: Direct Transformation of \a/\a, \b-Unsaturated \g-Hybrid
 Peptides to \a/\g-Hybrid Peptide 12-Helices.
;
_journal_issue                   11
_journal_name_full               'Organic letters'
_journal_page_first              2770
_journal_page_last               2773
_journal_paper_doi               10.1021/ol300987d
_journal_volume                  14
_journal_year                    2012
_chemical_absolute_configuration syn
_chemical_compound_source        Synthesis
_chemical_formula_moiety         'C35 H50 N5 O6, (C H2 Cl2)'
_chemical_formula_sum            'C36 H52 Cl2 N5 O6'
_chemical_formula_weight         721.73
_chemical_name_common            'Alpa-gamma helix'
_chemical_name_systematic        'Penta Peptide'
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_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                   10.5245(18)
_cell_length_b                   16.382(3)
_cell_length_c                   22.095(4)
_cell_measurement_temperature    100(2)
_cell_volume                     3809.5(12)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_pressure         101.325
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.945
_diffrn_measured_fraction_theta_max 0.945
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0343
_diffrn_reflns_av_sigmaI/netI    0.0670
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -4
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            15224
_diffrn_reflns_theta_full        28.56
_diffrn_reflns_theta_max         28.56
_diffrn_reflns_theta_min         1.55
_diffrn_source                   'fine-focus sealed tube'
_diffrn_source_type              'Graphite monochromator'
_exptl_absorpt_coefficient_mu    0.220
_exptl_absorpt_correction_T_max  0.941
_exptl_absorpt_correction_T_min  0.928
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.258
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'Square Block'
_exptl_crystal_F_000             1540
_exptl_crystal_recrystallization_method DCM/MeOH
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.32
_exptl_crystal_size_min          0.28
_refine_diff_density_max         0.280
_refine_diff_density_min         -0.262
_refine_diff_density_rms         0.043
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.09(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.015
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     449
_refine_ls_number_reflns         8813
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.015
_refine_ls_R_factor_all          0.0920
_refine_ls_R_factor_gt           0.0511
_refine_ls_shift/su_max          0.012
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0707P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1180
_refine_ls_wR_factor_ref         0.1428
_reflns_number_gt                5776
_reflns_number_total             8813
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol300987d_si_002.cif
_cod_data_source_block           G3
_cod_original_cell_volume        3809.4(11)
_cod_database_code               1507725