Design of peptides with α,β-dehydro residues: a dipeptide with a branched β-carbon dehydro residue at the (<i>i</i>+1) position, methyl <i>N</i>-(benzyloxycarbonyl)-α,β-didehydrovalyl-<small>L</small>-tryptophanate
Vijayaraghavan, Rangachari; Kumar, Pravindra; Dey, Sharmistha; Singh, Tej P.; Acta Crystallographica Section C 57 (2001) 1220–1221; doi:10.1107/S010827010100840X

data_2012283
_publ_section_title
;Design of peptides with \a,\b-dehydro residues: a dipeptide with a branched
 \b-carbon dehydro residue at the (<i>i</i>+1) position, methyl
 <i>N</i>-(benzyloxycarbonyl)-\a,\b-didehydrovalyl-<small>L</small>-tryptophanate
;
_journal_issue                   10
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              1220
_journal_page_last               1221
_journal_paper_doi               10.1107/S010827010100840X
_journal_volume                  57
_journal_year                    2001
_chemical_formula_iupac          'C25 H27 N3 O5'
_chemical_formula_moiety         'C25 H27 N3 O5'
_chemical_formula_sum            'C25 H27 N3 O5'
_chemical_formula_weight         449.50
_chemical_name_systematic
;
Methyl N-(carbobenzoxy)-\a,\b-didehydrovalyl-L-tryptophanate
;
_space_group_IT_number           5
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'A 2y'
_symmetry_space_group_name_H-M   'A 1 2 1'
_cell_angle_alpha                90.00
_cell_angle_beta                 107.791(12)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   17.1524(9)
_cell_length_b                   6.1439(9)
_cell_length_c                   22.6183(11)
_cell_measurement_reflns_used    25
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      25
_cell_measurement_theta_min      0
_cell_volume                     2269.6(4)
_computing_cell_refinement       SDP
_computing_data_collection       'SDP (Enraf-Nonius, 1979)'
_computing_molecular_graphics    'PLATON (Spek, 2001)'
_computing_publication_material  SHELXL97
_computing_structure_refinement  'SHELXL97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full .993
_diffrn_measured_fraction_theta_max .993
_diffrn_measurement_device_type  'Enraf Nonius CAD-4'
_diffrn_measurement_method       \w-2\q
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54180
_diffrn_reflns_av_R_equivalents  .0000
_diffrn_reflns_av_sigmaI/netI    .0170
_diffrn_reflns_limit_h_max       21
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            2576
_diffrn_reflns_theta_full        75.56
_diffrn_reflns_theta_max         75.56
_diffrn_reflns_theta_min         2.71
_diffrn_standards_decay_%        0
_diffrn_standards_interval_time  60
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    .759
_exptl_absorpt_correction_T_max  .928
_exptl_absorpt_correction_T_min  .835
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   '(SDP; Enraf-Nonius, 1979)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.315
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             952
_exptl_crystal_size_max          .3
_exptl_crystal_size_mid          .2
_exptl_crystal_size_min          .1
_refine_diff_density_max         .241
_refine_diff_density_min         -.249
_refine_ls_extinction_coef       .0018(4)
_refine_ls_extinction_method     SHELXL97
_refine_ls_goodness_of_fit_ref   1.040
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     302
_refine_ls_number_reflns         2576
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          .0484
_refine_ls_R_factor_gt           .0460
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         .000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.1137P)^2^+0.5403P] where P = (Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         .1455
_reflns_number_gt                2434
_reflns_number_total             2576
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            vj1138.cif
_cod_data_source_block           II
_cod_original_sg_symbol_H-M      'A 2'
_cod_database_code               2012283
_cod_database_fobs_code          2012283