Stereospecific synthetic approach towards Tamiflu using the Ramberg–Backlund reaction from cysteine hydrochloride
Chavan, Subhash P.; Chavan, Prakash N.; Gonnade, Rajesh G.; RSC Adv. 4 (2014) 62281–; doi:10.1039/C4RA10391B

data_7235720
_publ_section_title
;
 Stereospecific synthetic approach towards Tamiflu using the
 Ramberg--Backlund reaction from cysteine hydrochloride
;
_journal_issue                   107
_journal_name_full               'RSC Adv.'
_journal_page_first              62281
_journal_paper_doi               10.1039/C4RA10391B
_journal_volume                  4
_journal_year                    2014
_chemical_formula_sum            'C16 H28 N2 O5'
_chemical_formula_weight         328.40
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        '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                   5.0614(19)
_cell_length_b                   17.562(6)
_cell_length_c                   19.408(8)
_cell_measurement_temperature    296(2)
_cell_volume                     1725.1(11)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.913
_diffrn_measured_fraction_theta_max 0.913
_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  0.0658
_diffrn_reflns_av_sigmaI/netI    0.1130
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -5
_diffrn_reflns_limit_k_max       22
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            7277
_diffrn_reflns_theta_full        28.64
_diffrn_reflns_theta_max         28.64
_diffrn_reflns_theta_min         2.32
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  0.999
_exptl_absorpt_correction_T_min  0.988
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            clourless
_exptl_crystal_density_diffrn    1.264
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needles
_exptl_crystal_F_000             712
_exptl_crystal_size_max          0.150
_exptl_crystal_size_mid          0.110
_exptl_crystal_size_min          0.008
_refine_diff_density_max         0.442
_refine_diff_density_min         -0.273
_refine_diff_density_rms         0.078
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0(3)
_refine_ls_extinction_coef       0.022(8)
_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   1.016
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     215
_refine_ls_number_reflns         3998
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.016
_refine_ls_R_factor_all          0.1696
_refine_ls_R_factor_gt           0.0967
_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^)+(0.1785P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2631
_refine_ls_wR_factor_ref         0.3175
_reflns_number_gt                1939
_reflns_number_total             3998
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c4ra10391b2.cif
_cod_data_source_block           tfepoxy
_cod_original_cell_volume        1725.1(12)
_cod_database_code               7235720