Helical-screw directions of diastereoisomeric cyclic alpha-amino acid oligomers.
Nagano, Masanobu; Tanaka, Masakazu; Doi, Mitsunobu; Demizu, Yosuke; Kurihara, Masaaki; Suemune, Hiroshi; Organic letters 11 (2009) 1135–1137; doi:10.1021/ol802963a

data_1503802
_publ_section_title
;
 Helical-screw directions of diastereoisomeric cyclic alpha-amino acid
 oligomers.
;
_journal_issue                   5
_journal_name_full               'Organic letters'
_journal_page_first              1135
_journal_page_last               1137
_journal_paper_doi               10.1021/ol802963a
_journal_volume                  11
_journal_year                    2009
_chemical_absolute_configuration rm
_chemical_compound_source        synthesis
_chemical_formula_moiety         'C65 H98 N8 O19, 1.5(H2 O)'
_chemical_formula_sum            'C65 H101 N8 O20.5'
_chemical_formula_weight         1322.54
_chemical_melting_point          241
_chemical_name_common            Cbz-{(1R,3S)-Ac5cOM}8-OMe
_space_group_IT_number           1
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                71.492(3)
_cell_angle_beta                 87.501(3)
_cell_angle_gamma                89.647(4)
_cell_formula_units_Z            2
_cell_length_a                   9.995(16)
_cell_length_b                   17.515(3)
_cell_length_c                   20.382(3)
_cell_measurement_reflns_used    8905
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.4
_cell_measurement_theta_min      3.0
_cell_volume                     3380(5)
_computing_cell_refinement       'CrystalStructure 3.7.0'
_computing_data_collection       'CrystalStructure 3.7.0'
_computing_data_reduction        'CrystalStructure 3.7.0'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 10
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_diffrn_measurement_device_type  'Rigaku RAXIS-RAPID'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.1128
_diffrn_reflns_av_sigmaI/netI    0.1772
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            22257
_diffrn_reflns_theta_full        23.26
_diffrn_reflns_theta_max         23.26
_diffrn_reflns_theta_min         3.00
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.299
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1422
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.800
_refine_diff_density_min         -0.498
_refine_diff_density_rms         0.067
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.9(16)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.010
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           fullcycle
_refine_ls_number_parameters     1684
_refine_ls_number_reflns         9697
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.010
_refine_ls_R_factor_all          0.1192
_refine_ls_R_factor_gt           0.0800
_refine_ls_shift/su_max          0.008
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1478P)^2^+0.5018P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1990
_refine_ls_wR_factor_ref         0.2313
_reflns_number_gt                6650
_reflns_number_total             9697
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ol802963a_si_005.cif
_cod_data_source_block           nag5
_cod_original_sg_symbol_H-M      P1
_cod_original_formula_sum        'C65 H101 N8 O20.50'
_cod_database_code               1503802