Stereoconvergent [1,2]- and [1,4]-Wittig Rearrangements of 2-Silyl-6-aryl-5,6-dihydropyrans: A Tale of Steric vs Electronic Regiocontrol of Divergent Pathways.
Mori-Quiroz, Luis M; Maleczka, Jr, Robert E; The Journal of organic chemistry 80 (2015) 1163–; doi:10.1021/jo5026942

data_4030545
_publ_section_title
;
 Stereoconvergent [1,2]- and [1,4]-Wittig Rearrangements of
 2-Silyl-6-aryl-5,6-dihydropyrans: A Tale of Steric vs Electronic
 Regiocontrol of Divergent Pathways.
;
_journal_issue                   2
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              1163
_journal_paper_doi               10.1021/jo5026942
_journal_volume                  80
_journal_year                    2015
_chemical_formula_moiety         'C21 H28 O Si'
_chemical_formula_sum            'C21 H28 O Si'
_chemical_formula_weight         324.52
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_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_date             2013-03-14
_audit_creation_method
;
  Olex2 1.2
  (compiled Dec  5 2012 16:20:19, GUI svn.r4385)
;
_cell_angle_alpha                90.00
_cell_angle_beta                 92.0430(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.95030(10)
_cell_length_b                   8.14580(10)
_cell_length_c                   22.6084(3)
_cell_measurement_reflns_used    9965
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      68.211
_cell_measurement_theta_min      5.774
_cell_volume                     1831.32(4)
_computing_cell_refinement       'APEX2 (BRUKER, V2012.10-0, 2012)'
_computing_data_collection       'COSMO (BRUKER, V1.61, 2009)'
_computing_data_reduction        'SAINT v8.27A (Bruker, 2012)'
_computing_molecular_graphics
;
O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard and H. Puschmann,
OLEX2: a complete structure solution, refinement and analysis program.
J. Appl. Cryst. (2009). 42, 339-341.
;
_computing_publication_material
;
O. V. Dolomanov, L. J. Bourhis, R. J. Gildea, J. A. K. Howard and H. Puschmann,
OLEX2: a complete structure solution, refinement and analysis program.
J. Appl. Cryst. (2009). 42, 339-341.
;
_computing_structure_refinement
;
XL, G.M. Sheldrick, Acta Cryst.
(2008). A64, 112-122
;
_computing_structure_solution
;
XS, G.M. Sheldrick, Acta Cryst.
(2008). A64, 112-122
;
_diffrn_ambient_temperature      173.01
_diffrn_detector_area_resol_mean 836.6
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0372
_diffrn_reflns_av_unetI/netI     0.0186
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            31801
_diffrn_reflns_theta_full        68.31
_diffrn_reflns_theta_max         68.31
_diffrn_reflns_theta_min         3.91
_diffrn_source                   'fine-focus sealed tube'
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    1.131
_exptl_absorpt_correction_T_max  0.7531
_exptl_absorpt_correction_T_min  0.6739
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2012/1 (Bruker,2012) was used for absorption correction.
wR2(int) was 0.0751 before and 0.0447 after correction.
The Ratio of minimum to maximum transmission is 0.8948.
The \l/2 correction factor is 0.0015.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.177
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             704
_exptl_crystal_size_max          0.428
_exptl_crystal_size_mid          0.316
_exptl_crystal_size_min          0.191
_refine_diff_density_max         0.377
_refine_diff_density_min         -0.214
_refine_diff_density_rms         0.040
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.051
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     212
_refine_ls_number_reflns         3328
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.051
_refine_ls_R_factor_all          0.0354
_refine_ls_R_factor_gt           0.0329
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0427P)^2^+0.8454P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0867
_refine_ls_wR_factor_ref         0.0887
_reflns_number_gt                3081
_reflns_number_total             3328
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo5026942_si_002.cif
_cod_data_source_block           rem113
_cod_database_code               4030545
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  {H20A,H20B} of C20, {H18A,H18B} of C18, H12 of C12, H14 of C14, H11 of C11,
  H10 of C10, H9 of C9, H7 of C7, H5 of C5, H4 of C4, {H3A,H3B} of C3, H2 of C2,
   {H16A,H16B} of C16, H15 of C15
 At 1.5 times of:
  {H21A,H21B,H21C} of C21, {H19A,H19B,H19C} of C19, H1 of O1, {H17A,H17B,
  H17C} of C17
2.a Ternary CH refined with riding coordinates:
 C2(H2)
2.b Secondary CH2 refined with riding coordinates:
 C3(H3A,H3B), C16(H16A,H16B), C18(H18A,H18B), C20(H20A,H20B)
2.c Aromatic/amide H refined with riding coordinates:
 C4(H4), C5(H5), C7(H7), C9(H9), C10(H10), C11(H11), C12(H12), C14(H14),
 C15(H15)
2.d Idealised Me refined as rotating group:
 C17(H17A,H17B,H17C), C19(H19A,H19B,H19C), C21(H21A,H21B,H21C)
2.e Idealised tetrahedral OH refined as rotating group:
 O1(H1)
;
_contact_crystallographer_email  staples@chemistry.msu.com
_contact_crystallographer_name   'Richard Staples'