Dramatic influence of the substitution of alkylidene-5H-furan-2-ones in Diels-Alder cycloadditions with o-quinonedimethide as diene partner: en route to the CDEF polycyclic ring system of lactonamycin.
Dubois, Sébastien; Rodier, Fabien; Blanc, Romain; Rahmani, Raphaël; Héran, Virginie; Thibonnet, Jérôme; Commeiras, Laurent; Parrain, Jean-Luc; Organic & biomolecular chemistry 10 (2012) 4712–4719; doi:10.1039/c2ob25299f

data_7152372
_publ_section_title
;
 Dramatic influence of the substitution of alkylidene-5H-furan-2-ones in
 Diels-Alder cycloadditions with o-quinonedimethide as diene partner: en
 route to the CDEF polycyclic ring system of lactonamycin.
;
_journal_issue                   24
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              4712
_journal_page_last               4719
_journal_paper_doi               10.1039/c2ob25299f
_journal_volume                  10
_journal_year                    2012
_chemical_absolute_configuration unk
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         'C29 H46 O5 Si2'
_chemical_formula_sum            'C29 H46 O5 Si2'
_chemical_formula_weight         530.84
_space_group_IT_number           33
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      33
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_conform_dict_location     ftp://ftp.iucr.org/pub/cif_core.dic
_audit_conform_dict_name         cif_core.dic
_audit_conform_dict_version      2.4
_audit_creation_date             2011-10-04T17:28:34-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   25.2489(6)
_cell_length_b                   15.9776(3)
_cell_length_c                   7.6958(1)
_cell_measurement_reflns_used    15463
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      28.27
_cell_measurement_theta_min      1.51
_cell_measurement_wavelength     0.71073
_cell_volume                     3104.62(10)
_computing_molecular_graphics    'Ortep-3 for Windows (Farrugia, 1997)'
_computing_publication_material  'WinGX publication routines (Farrugia, 1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SIR92 (Giacovazzo et al, 1993)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.971
_diffrn_measured_fraction_theta_max 0.971
_diffrn_measurement_device_type  KappaCCD
_diffrn_measurement_method       'Omega + 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     0.041
_diffrn_reflns_limit_h_max       0
_diffrn_reflns_limit_h_min       -33
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       9
_diffrn_reflns_limit_l_min       0
_diffrn_reflns_number            15463
_diffrn_reflns_theta_full        28.27
_diffrn_reflns_theta_max         28.27
_diffrn_reflns_theta_min         1.51
_diffrn_standards_number         none
_exptl_absorpt_coefficient_mu    0.147
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.136
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             1152
_exptl_crystal_size_max          0.4
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.18
_refine_diff_density_max         0.336
_refine_diff_density_min         -0.381
_refine_diff_density_rms         0.109
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.3(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.183
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     325
_refine_ls_number_reflns         4009
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.183
_refine_ls_R_factor_all          0.0765
_refine_ls_R_factor_gt           0.054
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0900P)^2^+0.5646P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1436
_refine_ls_wR_factor_ref         0.1683
_reflns_number_gt                3256
_reflns_number_total             4009
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            c2ob25299f.txt
_cod_data_source_block           lcomoct2011
_cod_database_code               7152372