Betaine mediated synthesis of annulated dihydrofurans from oxobis(methylthio)ketene acetals and N-butyl-N'-methyl ethane-1,2-diamine as precursors via NHC elimination.
Kumar, Atul; Maurya, Shivam; Pratap, Kemant; Srivastava, Suman; Chemical communications (Cambridge, England) 52 (2016) 2795–2798; doi:10.1039/c5cc09509c

data_7118283
_publ_section_title
;
 Betaine mediated synthesis of annulated dihydrofurans from
 oxobis(methylthio)ketene acetals and N-butyl-N'-methyl ethane-1,2-diamine
 as precursors via NHC elimination.
;
_journal_issue                   13
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              2795
_journal_page_last               2798
_journal_paper_doi               10.1039/c5cc09509c
_journal_volume                  52
_journal_year                    2016
_chemical_formula_sum            'C27 H24 O3'
_chemical_formula_weight         396.46
_space_group_IT_number           14
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2012-07-16 deposited with the CCDC.
2016-01-05 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 92.094(6)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   18.7438(12)
_cell_length_b                   5.9398(4)
_cell_length_c                   19.1345(14)
_cell_measurement_temperature    293(2)
_cell_volume                     2128.9(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.853
_diffrn_measured_fraction_theta_max 0.853
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0288
_diffrn_reflns_av_sigmaI/netI    0.0524
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -23
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       26
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            9703
_diffrn_reflns_theta_full        29.10
_diffrn_reflns_theta_max         29.10
_diffrn_reflns_theta_min         3.26
_exptl_absorpt_coefficient_mu    0.079
_exptl_crystal_density_diffrn    1.237
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             840
_refine_diff_density_max         0.402
_refine_diff_density_min         -0.430
_refine_diff_density_rms         0.048
_refine_ls_extinction_coef       0.0021(12)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   1.022
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     265
_refine_ls_number_reflns         4871
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.022
_refine_ls_R_factor_all          0.1223
_refine_ls_R_factor_gt           0.0739
_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^)+(0.0711P)^2^+1.4688P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1674
_refine_ls_wR_factor_ref         0.1987
_reflns_number_gt                2947
_reflns_number_total             4871
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c5cc09509c2.cif
_cod_data_source_block           shelxl
_cod_depositor_comments
;
         Adding full bibliography for 7118283.cif.

2018-02-03
Z value and formula fixed to values more according to usual
chemical conventions.                 miguel
;
_cod_original_formula_sum        'C13.50 H12 O1.50 S0'
_cod_original_formula_units_Z    8
_cod_original_formula_weight     198.23
_cod_database_code               7118283