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_1503800
_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_sum            'C65 H101 N8 O21.5'
_chemical_formula_weight         1338.54
_chemical_melting_point          241
_chemical_name_common            Cbz-{(1S,3S)-Ac5cOM}8-OMe
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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                 93.955(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   17.6345(10)
_cell_length_b                   19.8515(12)
_cell_length_c                   19.6951(11)
_cell_measurement_reflns_used    21186
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3.0
_cell_volume                     6878.3(7)
_computing_cell_refinement       'Rigaku/MSC CrystalClear'
_computing_data_collection       'Rigaku/MSC CrystalClear'
_computing_data_reduction        'Rigaku/MSC CrystalClear'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 10.00
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_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     0.71073
_diffrn_reflns_av_R_equivalents  0.1157
_diffrn_reflns_av_sigmaI/netI    0.2085
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            30766
_diffrn_reflns_theta_full        20.82
_diffrn_reflns_theta_max         20.82
_diffrn_reflns_theta_min         3.00
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_T_max  0.9856
_exptl_absorpt_correction_T_min  0.9623
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Rigaku/MSC CrystalClear'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.293
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             2876
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.503
_refine_diff_density_min         -0.233
_refine_diff_density_rms         0.048
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.800
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           fullcycle
_refine_ls_number_parameters     1720
_refine_ls_number_reflns         7426
_refine_ls_number_restraints     1478
_refine_ls_restrained_S_all      1.775
_refine_ls_R_factor_all          0.1187
_refine_ls_R_factor_gt           0.0568
_refine_ls_shift/su_max          0.017
_refine_ls_shift/su_mean         0.003
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0759P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1317
_refine_ls_wR_factor_ref         0.1436
_reflns_number_gt                3222
_reflns_number_total             7426
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ol802963a_si_003.cif
_cod_data_source_block           nag3
_cod_original_formula_sum        'C65 H101 N8 O21.50'
_cod_database_code               1503800