A Short and Efficient Synthesis of (-)-7-Methylomuralide, a Potent Proteasome Inhibitor
Ryan A. Shenvi; E. J. Corey; Journal of the American Chemical Society 131 (2009) 5746–5747; doi:10.1021/ja901400q

data_4104257
_publ_section_title
;
 A Short and Efficient Synthesis of (-)-7-Methylomuralide, a Potent
 Proteasome Inhibitor
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              5746
_journal_page_last               5747
_journal_paper_doi               10.1021/ja901400q
_journal_volume                  131
_journal_year                    2009
_chemical_compound_source        'chemical synthesis'
_chemical_formula_iupac          'C20 H25 N O7'
_chemical_formula_moiety         'C20 H25 N O7'
_chemical_formula_structural     'C20 H25 N O7'
_chemical_formula_sum            'C20 H25 N O7'
_chemical_formula_weight         391.41
_chemical_name_common            RAS-2-OCbz
_chemical_name_systematic
; 
Methyl 2-(1-(benzyloxycarbonyloxy)-2-methylpropyl)-4,4-
dimethyl-3,5-dioxopyrrolidine-2-carboxylate
;
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                88.129(1)
_cell_angle_beta                 78.693(1)
_cell_angle_gamma                88.859(1)
_cell_formula_units_Z            2
_cell_length_a                   9.0015(1)
_cell_length_b                   9.1400(1)
_cell_length_c                   12.5776(1)
_cell_measurement_reflns_used    11624
_cell_measurement_temperature    193(2)
_cell_measurement_theta_max      27.44
_cell_measurement_theta_min      2.23
_cell_volume                     1014.084(18)
_computing_cell_refinement       'SAINT V7.34A (Bruker AXS, 2006b)'
_computing_data_collection       'APEX2 v2.1-0 (Bruker AXS, 2006a)'
_computing_data_reduction        'SAINT V7.34A (Bruker AXS, 2006b)'
_computing_molecular_graphics    'SHELXTL v6.12 (Bruker AXS, 2001)'
_computing_publication_material  'SHELXTL v6.12 (Bruker AXS, 2001)'
_computing_structure_refinement  'SHELXTL v6.12 (Bruker AXS, 2001)'
_computing_structure_solution    'SHELXTL v6.12 (Bruker AXS, 2001)'
_diffrn_ambient_temperature      193(2)
_diffrn_detector_area_resol_mean 836.6
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker APEX II CCD'
_diffrn_measurement_method       '\w scans, 3225 0.5\% rotations'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0232
_diffrn_reflns_av_sigmaI/netI    0.0140
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            29386
_diffrn_reflns_theta_full        27.50
_diffrn_reflns_theta_max         27.50
_diffrn_reflns_theta_min         1.65
_diffrn_standards_decay_%        0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.097
_exptl_absorpt_correction_T_max  0.9899
_exptl_absorpt_correction_T_min  0.9747
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Bruker AXS, 2004)'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.282
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Plate
_exptl_crystal_F_000             416
_exptl_crystal_size_max          0.265
_exptl_crystal_size_mid          0.175
_exptl_crystal_size_min          0.105
_refine_diff_density_max         0.324
_refine_diff_density_min         -0.176
_refine_diff_density_rms         0.036
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.041
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     261
_refine_ls_number_reflns         4666
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.041
_refine_ls_R_factor_all          0.0440
_refine_ls_R_factor_gt           0.0374
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0514P)^2^+0.2622P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0992
_refine_ls_wR_factor_ref         0.1044
_reflns_number_gt                4010
_reflns_number_total             4666
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ja901400q_si_003.cif
_cod_data_source_block           ejc158
_cod_database_code               4104257