Synthesis of 2,3,5,6-tetrasubstituted tetrahydropyrans via (3,5)-oxonium-ene reaction.
Saha, Pipas; Bhunia, Anup; Saikia, Anil K.; Organic & biomolecular chemistry 10 (2012) 2470–2481; doi:10.1039/c2ob06832j

data_7152256
_publ_section_title
;
 Synthesis of 2,3,5,6-tetrasubstituted tetrahydropyrans via
 (3,5)-oxonium-ene reaction.
;
_journal_issue                   12
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              2470
_journal_page_last               2481
_journal_paper_doi               10.1039/c2ob06832j
_journal_volume                  10
_journal_year                    2012
_chemical_formula_sum            'C23 H26 O4'
_chemical_formula_weight         366.44
_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
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 94.582(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   12.5282(8)
_cell_length_b                   8.7884(6)
_cell_length_c                   18.2013(12)
_cell_measurement_temperature    296(2)
_cell_volume                     1997.6(2)
_computing_cell_refinement       'Bruker Smart'
_computing_data_collection       'Bruker Smart'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.986
_diffrn_measured_fraction_theta_max 0.986
_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  0.0271
_diffrn_reflns_av_sigmaI/netI    0.0236
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -24
_diffrn_reflns_number            22711
_diffrn_reflns_theta_full        28.24
_diffrn_reflns_theta_max         28.24
_diffrn_reflns_theta_min         1.63
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  0.974
_exptl_absorpt_correction_T_min  0.961
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1997)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.218
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             784
_exptl_crystal_size_max          0.48
_exptl_crystal_size_mid          0.40
_exptl_crystal_size_min          0.32
_refine_diff_density_max         0.199
_refine_diff_density_min         -0.454
_refine_diff_density_rms         0.088
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.373
_refine_ls_hydrogen_treatment    none
_refine_ls_matrix_type           full
_refine_ls_number_parameters     247
_refine_ls_number_reflns         4878
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.373
_refine_ls_R_factor_all          0.0967
_refine_ls_R_factor_gt           0.0613
_refine_ls_shift/su_max          0.004
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1000P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1695
_refine_ls_wR_factor_ref         0.2108
_reflns_number_gt                3094
_reflns_number_total             4878
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob06832j.txt
_cod_data_source_block           ps_433l
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               7152256