Highly efficient synthesis of the tricyclic core of taxol by cascade metathesis.
Letort, Aurélien; Aouzal, Rémi; Ma, Cong; Long, De-Liang; Prunet, Joëlle; Organic letters 16 (2014) 3300–3303; doi:10.1021/ol501304j

data_1516522
_publ_section_title
;
 Highly efficient synthesis of the tricyclic core of taxol by cascade
 metathesis.
;
_journal_issue                   12
_journal_name_full               'Organic letters'
_journal_page_first              3300
_journal_page_last               3303
_journal_paper_doi               10.1021/ol501304j
_journal_volume                  16
_journal_year                    2014
_chemical_absolute_configuration yes
_chemical_formula_sum            'C26 H31 N O5'
_chemical_formula_weight         437.52
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   Delfmap
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.4950(6)
_cell_length_b                   10.4454(9)
_cell_length_c                   35.197(3)
_cell_measurement_reflns_used    1878
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      17.8
_cell_measurement_theta_min      2.27
_cell_volume                     2755.5(4)
_computing_cell_refinement       Apex2
_computing_data_collection       Apex2
_computing_data_reduction        Apex2
_computing_molecular_graphics    Diamond3
_computing_publication_material  WinGX
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_computing_structure_solution    'SHELXL-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.780
_diffrn_measured_fraction_theta_max 0.963
_diffrn_measurement_device_type  'Bruker Apex II Quasar'
_diffrn_measurement_method       '\w & \p scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0806
_diffrn_reflns_av_unetI/netI     0.1225
_diffrn_reflns_Laue_measured_fraction_full 0.780
_diffrn_reflns_Laue_measured_fraction_max 0.963
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       39
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            12353
_diffrn_reflns_point_group_measured_fraction_full 0.764
_diffrn_reflns_point_group_measured_fraction_max 0.952
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         23.296
_diffrn_reflns_theta_min         2.034
_diffrn_source                   'microfocus X-ray source'
_exptl_absorpt_coefficient_mu    0.073
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.786
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.055
_exptl_crystal_density_method    none
_exptl_crystal_description       lath
_exptl_crystal_F_000             936
_exptl_crystal_size_max          0.370
_exptl_crystal_size_mid          0.102
_exptl_crystal_size_min          0.060
_refine_diff_density_max         0.34
_refine_diff_density_min         -0.31
_refine_diff_density_rms         0.08
_refine_ls_abs_structure_details
;
 Flack x determined using 746 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
;
_refine_ls_abs_structure_Flack   -1.9(10)
_refine_ls_extinction_coef       0.103(15)
_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   1.054
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     276
_refine_ls_number_reflns         3802
_refine_ls_number_restraints     22
_refine_ls_restrained_S_all      1.059
_refine_ls_R_factor_all          0.1565
_refine_ls_R_factor_gt           0.1164
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1315P)^2^+7.4146P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2886
_refine_ls_wR_factor_ref         0.3085
_reflns_Friedel_coverage         0.696
_reflns_Friedel_fraction_full    0.741
_reflns_Friedel_fraction_max     0.938
_reflns_number_gt                2357
_reflns_number_total             3802
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol501304j_si_002.cif
_cod_data_source_block           jpal472
_cod_depositor_comments          'Adding full bibliography for 1516522.cif.'
_cod_database_code               1516522
_shelx_estimated_absorpt_t_min   0.974
_shelx_estimated_absorpt_t_max   0.996
_shelxl_version_number           2013-4