Asymmetric Diels-Alder Reactions of Chiral Cyclopropylidene Imide Dienophiles: Preparation of gem-Dimethyl- and Spirocyclopropane Norbornyl Carboxylic Acids
Jeffrey T. Kuethe; Dalian Zhao; Guy R. Humphrey; Michel Journet; Arlene E. McKeown; Journal of Organic Chemistry 71 (2006) 2192–2195; doi:10.1021/jo052516c

data_4021546
_publ_contact_author_address
; Process Research 
 Merck Research Laboratories 
 P.O. Box 2000 
 Rahway, NJ 07065 
 USA 
;
_publ_contact_author_email       jeffrey_kuethe@merck.com
_publ_contact_author_name        'Jeffrey T. Kuethe'
_publ_section_title
;
 Asymmetric Diels-Alder Reactions of Chiral Cyclopropylidene
 Imide Dienophiles: Preparation of gem-Dimethyl- and
 Spirocyclopropane Norbornyl Carboxylic Acids
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              2192
_journal_page_last               2195
_journal_paper_doi               10.1021/jo052516c
_journal_volume                  71
_journal_year                    2006
_chemical_absolute_configuration syn
_chemical_formula_moiety         'C20 H21 N O3'
_chemical_formula_sum            'C20 H21 N O3'
_chemical_formula_weight         323.38
_chemical_name_common            compound22
_chemical_name_systematic
; (3aS,8aR)-3-[(3S)-spiro[bicyclo[2.2.1]heptane-2,1'-cyclopropane]
  -5-en-3-ylcarbonyl]-3,3a,8,8a-tetrahydro-2H-indeno[1,2-d][1,3]oxazo-2-one 
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.7449(7)
_cell_length_b                   9.1351(8)
_cell_length_c                   20.2771(17)
_cell_measurement_reflns_used    7757
_cell_measurement_temperature    223(2)
_cell_measurement_theta_max      26.36
_cell_measurement_theta_min      2.33
_cell_volume                     1619.8(2)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      223(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.0464
_diffrn_reflns_av_sigmaI/netI    0.0260
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       25
_diffrn_reflns_limit_l_min       -25
_diffrn_reflns_number            17416
_diffrn_reflns_theta_full        26.38
_diffrn_reflns_theta_max         26.38
_diffrn_reflns_theta_min         2.01
_exptl_absorpt_coefficient_mu    0.089
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.326
_exptl_crystal_density_meas      0
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Block
_exptl_crystal_F_000             688
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.45
_exptl_crystal_size_min          0.23
_refine_diff_density_max         0.208
_refine_diff_density_min         -0.197
_refine_diff_density_rms         0.039
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     217
_refine_ls_number_reflns         1914
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.0368
_refine_ls_R_factor_gt           0.0336
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0542P)^2^+0.1643P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0847
_refine_ls_wR_factor_ref         0.0869
_reflns_number_gt                1768
_reflns_number_total             1914
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo052516csi20051207_021218.cif
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
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_cod_database_code               4021546