Enyne-2-pyrone [4 + 4]-Photocycloaddition: Sesquiterpene Synthesis and a Low-Temperature Cope Rearrangement.
Khatri, Buddha B.; Sieburth, Scott McN; Organic letters 17 (2015) 4360–4363; doi:10.1021/acs.orglett.5b02207

data_1555257
_publ_section_title
;
 Enyne-2-pyrone [4 + 4]-Photocycloaddition: Sesquiterpene Synthesis and a
 Low-Temperature Cope Rearrangement.
;
_journal_issue                   17
_journal_name_full               'Organic letters'
_journal_page_first              4360
_journal_page_last               4363
_journal_paper_doi               10.1021/acs.orglett.5b02207
_journal_volume                  17
_journal_year                    2015
_chemical_formula_moiety         'C20 H28 O3 Si'
_chemical_formula_sum            'C20 H28 O3 Si'
_chemical_formula_weight         344.51
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 92.333(2)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   34.403(3)
_cell_length_b                   6.7764(6)
_cell_length_c                   16.1333(16)
_cell_measurement_temperature    130(2)
_cell_volume                     3758.0(6)
_computing_cell_refinement       'SAINT (Bruker-AXS)'
_computing_data_collection       'COSMO (Bruker-AXS)'
_computing_data_reduction        'SADABS (BRuker-AXS)'
_computing_molecular_graphics    XP
_computing_publication_material  'APEX2 report generator (Bruker-AXS)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXL-2014/7 (Sheldrick,2014)'
_diffrn_ambient_temperature      130(2)
_diffrn_detector_area_resol_mean 8.333
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Kappa APEX II DUO'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0278
_diffrn_reflns_av_unetI/netI     0.0163
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       45
_diffrn_reflns_limit_h_min       -45
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            30345
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.012
_diffrn_reflns_theta_min         2.370
_exptl_absorpt_coefficient_mu    0.139
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
6672 Corrected reflections written to file mo_2329_0m.hkl
 Estimated minimum and maximum transmission:  0.6092  0.7457
 The ratio of these values is more reliable than their absolute values!
 Additional spherical absorption correction applied with mu*r =  0.2000
 Lambda/2 correction factor = 0.00150
;
_exptl_crystal_density_diffrn    1.218
_exptl_crystal_description       block
_exptl_crystal_F_000             1488
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.190
_exptl_crystal_size_min          0.175
_exptl_transmission_factor_max   0.7457
_exptl_transmission_factor_min   0.6092
_refine_diff_density_max         0.416
_refine_diff_density_min         -0.256
_refine_diff_density_rms         0.042
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.044
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     221
_refine_ls_number_reflns         4528
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.044
_refine_ls_R_factor_all          0.0376
_refine_ls_R_factor_gt           0.0326
_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^)+(0.0449P)^2^+3.2218P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0862
_refine_ls_wR_factor_ref         0.0910
_reflns_Friedel_coverage         0.000
_reflns_number_gt                4048
_reflns_number_total             4528
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol5b02207_si_001.cif
_cod_data_source_block           mo_2329_0m
_cod_original_sg_symbol_H-M      'C 2/c'
_cod_database_code               1555257
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              75267
_shelx_hkl_checksum              1938