Novel annulation reactions of aryl methyl ketenes with zwitterions derived from dimethyl acetylenedicarboxylate and N-alkylimidazoles.
Ma, Cheng; Ding, Hanfeng; Wang, Yanguang; Organic letters 8 (2006) 3133–3136; doi:10.1021/ol061126p

data_1506085
_publ_section_title
;
 Novel annulation reactions of aryl methyl ketenes with zwitterions
 derived from dimethyl acetylenedicarboxylate and N-alkylimidazoles.
;
_journal_issue                   14
_journal_name_full               'Organic letters'
_journal_page_first              3133
_journal_page_last               3136
_journal_paper_doi               10.1021/ol061126p
_journal_volume                  8
_journal_year                    2006
_chemical_formula_moiety         'C20 H20 N2 O4 '
_chemical_formula_sum            'C20 H20 N2 O4'
_chemical_formula_weight         352.39
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_Int_Tables_number      2
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_cell_angle_alpha                82.041(19)
_cell_angle_beta                 80.510(19)
_cell_angle_gamma                75.84(2)
_cell_formula_units_Z            2
_cell_length_a                   9.608(5)
_cell_length_b                   9.883(5)
_cell_length_c                   10.123(4)
_cell_measurement_reflns_used    7588
_cell_measurement_temperature    296(1)
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3.1
_cell_volume                     914.4(8)
_computing_cell_refinement       PROCESS-AUTO
_computing_data_collection       PROCESS-AUTO
_computing_data_reduction        CrystalStructure
_computing_publication_material  'CrystalStructure 3.7.0'
_computing_structure_refinement  CRYSTALS
_computing_structure_solution    SIR97
_diffrn_detector_area_resol_mean 10.00
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Rigaku RAXIS-RAPID'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.026
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -12
_diffrn_reflns_number            9099
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_exptl_absorpt_coefficient_mu    0.090
_exptl_absorpt_correction_T_max  0.980
_exptl_absorpt_correction_T_min  0.968
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
    Higashi, T. (1995). Program for Absorption Correction.
    Rigaku Corporation, Tokyo, Japan.
;
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.280
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             372.00
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.28
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.23
_refine_diff_density_min         -0.19
_refine_ls_extinction_coef       168(33)
_refine_ls_extinction_method
'Larson (1970) Crystallographic Computing eq. 22'
_refine_ls_goodness_of_fit_ref   1.006
_refine_ls_hydrogen_treatment    constr
_refine_ls_number_parameters     236
_refine_ls_number_reflns         3008
_refine_ls_R_factor_gt           0.0442
_refine_ls_shift/su_max          0.0000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[0.0026Fo^2^ + 1.0000\s(Fo^2^)]/(4Fo^2^)'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1311
_reflns_number_gt                3008
_reflns_number_total             4167
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            ol061126psi20060508_030932.cif
_cod_data_source_block           '_mc-dhf-3-4'
_cod_original_formula_sum        'C20 H20 N2 O4 '
_cod_database_code               1506085