Synthesis of pyroglutamic acid derivatives via double michael reactions of alkynones.
Scansetti, Myriam; Hu, Xiangping; McDermott, Benjamin P.; Lam, Hon Wai; Organic letters 9 (2007) 2159–2162; doi:10.1021/ol070674f

data_1505406
_publ_section_title
;
 Synthesis of pyroglutamic acid derivatives via double michael reactions
 of alkynones.
;
_journal_issue                   11
_journal_name_full               'Organic letters'
_journal_page_first              2159
_journal_page_last               2162
_journal_paper_doi               10.1021/ol070674f
_journal_volume                  9
_journal_year                    2007
_chemical_compound_source        'M. Scansetti'
_chemical_formula_moiety         'C28.00 H31.00 N1 O9'
_chemical_formula_sum            'C28 H31 N O9'
_chemical_formula_weight         525.55
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             07-01-17
_audit_creation_method           CRYSTALS_ver_12.84
_cell_angle_alpha                90
_cell_angle_beta                 97.855(4)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.5166(5)
_cell_length_b                   16.9331(10)
_cell_length_c                   21.0741(11)
_cell_measurement_reflns_used    5391
_cell_measurement_temperature    150
_cell_measurement_theta_max      29
_cell_measurement_theta_min      2
_cell_volume                     2657.1(3)
_computing_cell_refinement       'SAINT (Siemens ,1995)'
_computing_data_collection       'SMART (Siemens, 1993)'
_computing_data_reduction        'SAINT (Siemens ,1995)'
_computing_molecular_graphics    'CAMERON (Watkin et al., 1996)'
_computing_publication_material  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_refinement  'CRYSTALS (Betteridge et al., 2003)'
_computing_structure_solution    'SHELXS 86 (Sheldrick, 1986)'
_diffrn_ambient_temperature      150
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.935
_diffrn_measurement_device_type  'Bruker SMART Apex CCD'
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
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_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       30
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            37166
_diffrn_reflns_theta_full        28.400
_diffrn_reflns_theta_max         30.537
_diffrn_reflns_theta_min         1.951
_diffrn_standards_number         0
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_exptl_absorpt_correction_T_min  0.49
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_exptl_absorpt_process_details   'SADABS version 2006/1'
_exptl_crystal_colour            colourless
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_exptl_crystal_description       block
_exptl_crystal_F_000             1111.997
_exptl_crystal_recrystallization_method
'Recrystallisation by evaporation of hexane/diethyl ether solution'
_exptl_crystal_size_max          0.77
_exptl_crystal_size_mid          0.35
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.31
_refine_diff_density_min         -0.37
_refine_ls_extinction_method     None
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_refine_ls_hydrogen_treatment    constr
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_refine_ls_shift/su_max          0.000319
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
 Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982) 
 [weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)] 
 where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax 
 Method = Robust Weighting (Prince, 1982) 
 W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^ 
 A~i~ are: 
 125. 210. 126. 49.7 9.95 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.1943
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_refine_ls_wR_factor_ref         0.1943
_reflns_limit_h_max              9
_reflns_limit_h_min              -10
_reflns_limit_k_max              23
_reflns_limit_k_min              0
_reflns_limit_l_max              30
_reflns_limit_l_min              0
_reflns_number_gt                4145
_reflns_number_total             7610
_reflns_threshold_expression     I>2.0\s(I)
_oxford_diffrn_Wilson_B_factor   1.77
_oxford_diffrn_Wilson_scale      8.76
_oxford_refine_ls_scale          0.3713(7)
_cod_data_source_file            ol070674fsi20070319_025823.cif
_cod_data_source_block           hl7001
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to /home/saulius/struct/CIF-dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_original_formula_sum        'C28.00 H31.00 N1 O9'
_cod_database_code               1505406