Left-Handed Helical Preference in an Achiral Peptide Chain Is Induced by an l-Amino Acid in an N-Terminal Type II β-Turn
Matteo De Poli; Marta De Zotti; James Raftery; Juan A. Aguilar; Gareth A. Morris; Jonathan Clayden; Journal of Organic Chemistry 78 (2013) 2248–2255; doi:10.1021/jo302705k

data_4028042
_publ_contact_author_address
; 
Department of Chemistry 
University of Manchester 
Manchester M13 9PL 
England  UK 
;
_publ_contact_author_email       jrtest@spec.ch.man.ac.uk
_publ_contact_author_fax         44(161)275-4734
_publ_contact_author_name        'Raftery, James'
_publ_contact_author_phone       44(161)275-4700
_publ_section_title
;
 Left-Handed Helical Preference in an Achiral Peptide Chain Is Induced by
 an l-Amino Acid in an N-Terminal Type II \b-Turn
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              2248
_journal_page_last               2255
_journal_paper_doi               10.1021/jo302705k
_journal_volume                  78
_journal_year                    2013
_chemical_absolute_configuration syn
_chemical_formula_sum            'C24 H43 N5 O7'
_chemical_formula_weight         513.63
_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                 94.826(4)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   11.926(2)
_cell_length_b                   8.7132(17)
_cell_length_c                   13.814(3)
_cell_measurement_reflns_used    1463
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      19.6
_cell_measurement_theta_min      2.761
_cell_volume                     1430.4(5)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.951
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega 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  0.0673
_diffrn_reflns_av_sigmaI/netI    0.0955
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            12382
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         28.28
_diffrn_reflns_theta_min         1.48
_exptl_absorpt_coefficient_mu    0.088
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.193
_exptl_crystal_description       plate
_exptl_crystal_F_000             556
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.21
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.239
_refine_diff_density_min         -0.221
_refine_diff_density_rms         0.050
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.6(16)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.021
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     338
_refine_ls_number_reflns         3594
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.021
_refine_ls_R_factor_all          0.0914
_refine_ls_R_factor_gt           0.0681
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0399P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1087
_refine_ls_wR_factor_ref         0.1178
_reflns_number_gt                2802
_reflns_number_total             3594
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo302705k_si_002.cif
_cod_data_source_block           s3612m
_cod_original_cell_volume        1430.3(5)
_cod_database_code               4028042