Diastereoselective synthesis of 6-trifluoromethyl-5,6-dihydropyrans via phosphine-catalyzed [4 + 2] annulation of α-benzylallenoates with ketones.
Wang, Tong; Ye, Song; Organic letters 12 (2010) 4168–4171; doi:10.1021/ol101762z

data_1503202
_publ_section_title
;
 Diastereoselective synthesis of 6-trifluoromethyl-5,6-dihydropyrans via
 phosphine-catalyzed [4 + 2] annulation of \a-benzylallenoates with
 ketones.
;
_journal_issue                   18
_journal_name_full               'Organic letters'
_journal_page_first              4168
_journal_page_last               4171
_journal_paper_doi               10.1021/ol101762z
_journal_volume                  12
_journal_year                    2010
_chemical_formula_moiety         'C21 H18 Br F3 O3'
_chemical_formula_sum            'C21 H18 Br F3 O3'
_chemical_formula_weight         455.26
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_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                86.746(10)
_cell_angle_beta                 84.069(9)
_cell_angle_gamma                79.233(10)
_cell_formula_units_Z            4
_cell_length_a                   9.156(2)
_cell_length_b                   10.791(3)
_cell_length_c                   20.165(6)
_cell_measurement_reflns_used    456
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      2.17
_cell_volume                     1945.4(9)
_computing_cell_refinement       'CrystalClear (Rigaku Inc., 2007)'
_computing_data_collection       'CrystalClear (Rigaku Inc., 2007)'
_computing_data_reduction        'CrystalClear (Rigaku Inc., 2007)'
_computing_molecular_graphics    'XP in Siemens SHELXTL (Sheldrick, 1994)'
_computing_publication_material  'SHELX97 (Sheldrick, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Saturn724+ CCD'
_diffrn_measurement_method       '\w scans at fixed \c = 45\%'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0586
_diffrn_reflns_av_sigmaI/netI    0.0612
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            21608
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.02
_exptl_absorpt_coefficient_mu    2.160
_exptl_absorpt_correction_T_max  0.7816
_exptl_absorpt_correction_T_min  0.6972
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   'CrystalClear (Rigaku Inc., 2007)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.554
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             920
_exptl_crystal_size_max          0.18
_exptl_crystal_size_mid          0.17
_exptl_crystal_size_min          0.12
_refine_diff_density_max         0.487
_refine_diff_density_min         -0.437
_refine_diff_density_rms         0.071
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.170
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     507
_refine_ls_number_reflns         6835
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.170
_refine_ls_R_factor_all          0.0751
_refine_ls_R_factor_gt           0.0627
_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^)+(0.0218P)^2^+2.4334P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1077
_refine_ls_wR_factor_ref         0.1138
_reflns_number_gt                5873
_reflns_number_total             6835
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol101762z_si_002.cif
_cod_data_source_block           sa720
_cod_original_cell_volume        1945.3(9)
_cod_original_sg_symbol_H-M      P-1
_cod_database_code               1503202