Regenerative γ-Lactone Annulations: A Modular, Iterative Approach to Oligo-tetrahydrofuran Molecular Stairs and Related Frameworks.
Rashid, Showkat; Bhat, Bilal A.; Mehta, Goverdhan; Organic letters 17 (2015) 3604–3607; doi:10.1021/acs.orglett.5b01707

data_1555105
_publ_section_title
;
 Regenerative \g-Lactone Annulations: A Modular, Iterative Approach to
 Oligo-tetrahydrofuran Molecular Stairs and Related Frameworks.
;
_journal_issue                   14
_journal_name_full               'Organic letters'
_journal_page_first              3604
_journal_page_last               3607
_journal_paper_doi               10.1021/acs.orglett.5b01707
_journal_volume                  17
_journal_year                    2015
_chemical_compound_source        'see text'
_chemical_formula_iupac          'C8 H10 O4'
_chemical_formula_moiety         'C8 H10 O4'
_chemical_formula_structural     'C8 H10 O4'
_chemical_formula_sum            'C8 H10 O4'
_chemical_formula_weight         170.16
_chemical_name_systematic
(3a<i>R</i>,3b<i>R</i>,6a<i>S</i>,7a<i>R</i>)-hexahydrodifuro[2,3-<i>b</i>:3',2'-<i>d</i>]furan-2(3<i>H</i>)-one
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      29
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.571(6)
_cell_length_b                   5.838(3)
_cell_length_c                   12.338(7)
_cell_measurement_reflns_used    2586
_cell_measurement_temperature    291(2)
_cell_measurement_theta_max      26.03
_cell_measurement_theta_min      3.30
_cell_volume                     761.4(7)
_computing_cell_refinement       'SMART (Bruker, 1998)'
_computing_data_collection       'SMART (Bruker, 1998)'
_computing_data_reduction        'SAINT (Bruker, 1998)'
_computing_molecular_graphics
'PLATON (Spek, 2003) and CAMERON (Watkin et al., 1993)'
_computing_publication_material  'PLATON (Spek, 2003)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SIR92 (Altomare et al., 1994)'
_diffrn_ambient_temperature      291(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker AXS SMART APEX CCD area-detector'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoKa
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0204
_diffrn_reflns_av_sigmaI/netI    0.0141
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       14
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            4994
_diffrn_reflns_reduction_process
;
;
_diffrn_reflns_theta_full        25.35
_diffrn_reflns_theta_max         25.35
_diffrn_reflns_theta_min         3.30
_exptl_absorpt_coefficient_mu    0.120
_exptl_absorpt_correction_T_max  0.9964
_exptl_absorpt_correction_T_min  0.9672
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 2003)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.484
_exptl_crystal_density_method    'Not Measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             360
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.24
_exptl_crystal_size_min          0.03
_refine_diff_density_max         0.353
_refine_diff_density_min         -0.267
_refine_diff_density_rms         0.080
_refine_ls_abs_structure_details 'see text'
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.122
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     109
_refine_ls_number_reflns         733
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.122
_refine_ls_R_factor_all          0.0623
_refine_ls_R_factor_gt           0.0580
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0950P)^2^+0.1423P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1408
_refine_ls_wR_factor_ref         0.1440
_reflns_number_gt                661
_reflns_number_total             733
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            ol5b01707_si_002.cif
_cod_data_source_block           compound_16
_cod_database_code               1555105