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_1555256
_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         'C21 H30 O4 Si'
_chemical_formula_sum            'C21 H30 O4 Si'
_chemical_formula_weight         374.54
_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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_date             2015-07-27
_audit_creation_method
;
Olex2 1.2
(compiled 2014.11.20 svn.r3092 for OlexSys, GUI svn.r4949)
;
_cell_angle_alpha                90
_cell_angle_beta                 117.571(7)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   15.860(3)
_cell_length_b                   8.9849(15)
_cell_length_c                   32.138(4)
_cell_measurement_reflns_used    5893
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.121
_cell_measurement_theta_min      2.377
_cell_volume                     4059.6(12)
_computing_cell_refinement       'SAINT (Bruker AXS)'
_computing_data_collection       'COSMO (Bruker AXS)'
_computing_data_reduction        'SADABS (Bruker AXS)'
_computing_molecular_graphics    'Mercury (CCDC)'
_computing_publication_material  'APEX2 (Bruker AXS)'
_computing_structure_refinement
'XL (Sheldrick, 2008), OLEX2 (Dolomanov et al., 2009)'
_computing_structure_solution    XS
_diffrn_ambient_temperature      100.15
_diffrn_detector_area_resol_mean 8.333
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Bruker Kappa APEX II DUO'
_diffrn_measurement_method       '\f, \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0418
_diffrn_reflns_av_unetI/netI     0.0485
_diffrn_reflns_Laue_measured_fraction_full 0.998
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       18
_diffrn_reflns_limit_h_min       -18
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       32
_diffrn_reflns_limit_l_min       -38
_diffrn_reflns_number            22717
_diffrn_reflns_point_group_measured_fraction_full 0.998
_diffrn_reflns_point_group_measured_fraction_max 0.998
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         24.999
_diffrn_reflns_theta_min         1.430
_diffrn_source                   'Fine Focus Sealed Tube'
_exptl_absorpt_coefficient_mu    0.138
_exptl_absorpt_correction_T_max  0.7456
_exptl_absorpt_correction_T_min  0.6512
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2012/1 (Bruker,2012) was used for absorption correction.
wR2(int) was 0.0624 before and 0.0510 after correction.
The Ratio of minimum to maximum transmission is 0.8734.
The \l/2 correction factor is 0.0015.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.226
_exptl_crystal_description       prism
_exptl_crystal_F_000             1616
_exptl_crystal_size_max          0.66
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.15
_exptl_transmission_factor_max   0.7456
_exptl_transmission_factor_min   0.6512
_refine_diff_density_max         1.378
_refine_diff_density_min         -0.423
_refine_diff_density_rms         0.068
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.072
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     502
_refine_ls_number_reflns         7150
_refine_ls_number_restraints     6
_refine_ls_restrained_S_all      1.072
_refine_ls_R_factor_all          0.0889
_refine_ls_R_factor_gt           0.0651
_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^)+(0.0884P)^2^+4.6436P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1741
_refine_ls_wR_factor_ref         0.1884
_reflns_Friedel_coverage         0.000
_reflns_number_gt                5319
_reflns_number_total             7150
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol5b02207_si_002.cif
_cod_data_source_block           mo_2172_0m
_cod_depositor_comments
;
The following automatic conversions were performed:

data item '_atom_sites_solution_secondary' value 'diffmap' was
changed to 'difmap'.

Automatic conversion script
Id: cif_fix_values 6909 2019-04-08 15:41:33Z antanas 
;
_cod_database_code               1555256
_shelxl_version_number           2014/6
_shelx_estimated_absorpt_t_max   0.980
_shelx_estimated_absorpt_t_min   0.914
_exptl_absorpt_special_details
;
29187 Corrected reflections written to file
 Estimated minimum and maximum transmission:  0.6512  0.7456
 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 = 0.0015
;
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups
2. Rigid bond restraints
 C21A, C21B
 with sigma for 1-2 distances of 0.01 and sigma for 1-3 distances of 0.01
3. Uiso/Uaniso restraints and constraints
C21A \\sim C21B: within 1.7A with sigma of 0.01 and sigma for terminal atoms of
0.02
4. Others
 Sof(H20B)=Sof(C21B)=Sof(H21D)=Sof(H21E)=Sof(H21F)=Sof(C22B)=Sof(H22D)=
 Sof(H22E)=Sof(H22F)=1-FVAR(1)
 Sof(H20A)=Sof(C21A)=Sof(H21A)=Sof(H21B)=Sof(H21C)=Sof(C22A)=Sof(H22A)=
 Sof(H22B)=Sof(H22C)=FVAR(1)
5.a Ternary CH refined with riding coordinates:
 C17(H17), C20(H20), C17A(H17A), C20A(H20A), C20A(H20B)
5.b Secondary CH2 refined with riding coordinates:
 C3(H3A,H3B), C8(H8A,H8B), C14(H14C,H14D), C15(H15C,H15D), C16(H16C,H16D),
 C3A(H3AA,H3AB), C8A(H8AA,H8AB), C14A(H14A,H14B), C15A(H15A,H15B), C16A(H16A,
 H16B)
5.c Idealised Me refined as rotating group:
 C18(H18D,H18E,H18F), C19(H19D,H19E,H19F), C21(H21G,H21H,H21I), C22(H22G,H22H,
 H22I), C23(H23D,H23E,H23F), C24(H24D,H24E,H24F), C18A(H18A,H18B,H18C),
 C19A(H19A,H19B,H19C), C21A(H21A,H21B,H21C), C22A(H22A,H22B,H22C), C23A(H23A,
 H23B,H23C), C24A(H24A,H24B,H24C), C21B(H21D,H21E,H21F), C22B(H22D,H22E,H22F)
;
_shelx_res_checksum              88799
_shelx_hkl_checksum              23356
_olex2_submission_special_instructions 'No special instructions were received'