A Nonpeptidic Reverse Turn that Promotes Parallel Sheet Structure Stabilized by CH...O Hydrogen Bonds in a Cyclopropane γ-Peptide
Christopher R. Jones; M. Khurram N. Qureshi; Fiona R. Truscott; Shang-Te Danny Hsu; Angus J. Morrison; Martin D. Smith; Angewandte Chemie, International Edition 47 (2008) 7099–7102; doi:10.1002/anie.200802648

data_1508969
_publ_section_title
;
 A Nonpeptidic Reverse Turn that Promotes Parallel Sheet Structure
 Stabilized by CH...O Hydrogen Bonds in a Cyclopropane \g-Peptide
;
_journal_name_full               'Angewandte Chemie, International Edition'
_journal_page_first              7099
_journal_page_last               7102
_journal_paper_doi               10.1002/anie.200802648
_journal_volume                  47
_journal_year                    2008
_chemical_absolute_configuration
;
1119 Friedel pairs were averaged for the refinement
;
_chemical_formula_moiety         'C19 H25 F3 N2 O4, 0.5(C6 H14)'
_chemical_formula_sum            'C22 H32 F3 N2 O4'
_chemical_formula_weight         445.50
_chemical_name_systematic
;
?
;
_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                   5.6434(2)
_cell_length_b                   15.4253(8)
_cell_length_c                   26.7211(7)
_cell_measurement_reflns_used    10538
_cell_measurement_temperature    260(2)
_cell_measurement_theta_max      22.46
_cell_measurement_theta_min      1.00
_cell_volume                     2326.10(16)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_collection       'Collect (Nonius B.V. 1998)'
_computing_data_reduction
;
HKL Denzo and Scalepack (Otwinowski & Minor 1997)
;
_computing_publication_material  'SHELXL-97 (Sheldrick 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick 1997)'
_computing_structure_solution    'SIR-92 (Altomare et al. 1994)'
_diffrn_ambient_temperature      260(2)
_diffrn_measured_fraction_theta_full 0.953
_diffrn_measured_fraction_theta_max 0.953
_diffrn_measurement_device_type  'Nonius Kappa CCD'
_diffrn_measurement_method       'Thin slice \w and \f scans'
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0305
_diffrn_reflns_av_sigmaI/netI    0.0271
_diffrn_reflns_limit_h_max       4
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            6991
_diffrn_reflns_theta_full        22.41
_diffrn_reflns_theta_max         22.41
_diffrn_reflns_theta_min         3.69
_exptl_absorpt_coefficient_mu    0.103
_exptl_absorpt_correction_T_max  0.973
_exptl_absorpt_correction_T_min  0.860
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
multi-scan from symmetry-related measurements
Sortav (Blessing 1995)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.272
_exptl_crystal_description       block
_exptl_crystal_F_000             948
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.25
_refine_diff_density_max         0.420
_refine_diff_density_min         -0.213
_refine_diff_density_rms         0.055
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   5(4)
_refine_ls_extinction_coef       0.032(13)
_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   1.047
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     276
_refine_ls_number_reflns         1698
_refine_ls_number_restraints     9
_refine_ls_restrained_S_all      1.047
_refine_ls_R_factor_all          0.1032
_refine_ls_R_factor_gt           0.0923
_refine_ls_shift/su_max          0.092
_refine_ls_shift/su_mean         0.006
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1922P)^2^+1.2533P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2589
_refine_ls_wR_factor_ref         0.2753
_reflns_number_gt                1442
_reflns_number_total             1698
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            prev_ja301318a_3.cif
_cod_data_source_block           10
_cod_database_code               1508969