Diels-Alder cycloaddition of o-quinonedimethides and alkylidene-5H-furan-2-ones: new and rapid access to lambertellol cores and arthrinone derivatives.
Blanc, Romain; Héran, Virginie; Rahmani, Raphaël; Commeiras, Laurent; Parrain, Jean-Luc; Organic & biomolecular chemistry 8 (2010) 5490–5494; doi:10.1039/c0ob00448k

data_7153502
_publ_section_title
;
 Diels-Alder cycloaddition of o-quinonedimethides and
 alkylidene-5H-furan-2-ones: new and rapid access to lambertellol cores
 and arthrinone derivatives.
;
_journal_issue                   24
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              5490
_journal_page_last               5494
_journal_paper_doi               10.1039/c0ob00448k
_journal_volume                  8
_journal_year                    2010
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         'C26 H42 O4 Si2'
_chemical_formula_sum            'C26 H42 O4 Si2'
_chemical_formula_weight         474.78
_space_group_IT_number           61
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      61
_symmetry_space_group_name_Hall  '-P 2ac 2ab'
_symmetry_space_group_name_H-M   'P b c a'
_audit_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.3
_audit_creation_date             2009-02-03T09:06:31-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   10.40660(10)
_cell_length_b                   20.7845(2)
_cell_length_c                   26.5729(4)
_cell_measurement_reflns_used    52846
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28.27
_cell_measurement_theta_min      1.96
_cell_measurement_wavelength     0.71073
_cell_volume                     5747.61(12)
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-86 (Sheldrick, 1986)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.975
_diffrn_measured_fraction_theta_max 0.975
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       'Phi scan'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.052
_diffrn_reflns_av_unetI/netI     0.0287
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       26
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            52846
_diffrn_reflns_theta_full        28.27
_diffrn_reflns_theta_max         28.27
_diffrn_reflns_theta_min         1.96
_diffrn_source                   'fine-focus sealed tube'
_diffrn_standards_number         none
_exptl_absorpt_coefficient_mu    0.15
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.097
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             2064
_exptl_crystal_size_max          0.3
_exptl_crystal_size_mid          0.2
_exptl_crystal_size_min          0.2
_refine_diff_density_max         0.269
_refine_diff_density_min         -0.268
_refine_diff_density_rms         0.056
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.063
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     352
_refine_ls_number_reflns         6932
_refine_ls_number_restraints     34
_refine_ls_restrained_S_all      1.063
_refine_ls_R_factor_all          0.0964
_refine_ls_R_factor_gt           0.0688
_refine_ls_shift/su_max          0.281
_refine_ls_shift/su_mean         0.011
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0970P)^2^+2.2284P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1816
_refine_ls_wR_factor_ref         0.2044
_reflns_number_gt                5081
_reflns_number_total             6932
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c0ob00448k.txt
_cod_data_source_block           rra05103
_cod_database_code               7153502