Cycloaddition of delta2-thiazolines and acyl ketenes under acidic conditions results in bicyclic 1,3-oxazinones and not 6-acylpenams as earlier reported.
Pemberton, Nils; Emtenäs, Hans; Boström, Dan; Domaille, Peter J.; Greenberg, William A.; Levin, Michael D.; Zhu, Zuolin; Almqvist, Fredrik; Organic letters 7 (2005) 1019–1021; doi:10.1021/ol047528j

data_1506466
_publ_section_title
;
 Cycloaddition of delta2-thiazolines and acyl ketenes under acidic
 conditions results in bicyclic 1,3-oxazinones and not 6-acylpenams as
 earlier reported.
;
_journal_issue                   6
_journal_name_full               'Organic letters'
_journal_page_first              1019
_journal_page_last               1021
_journal_paper_doi               10.1021/ol047528j
_journal_volume                  7
_journal_year                    2005
_chemical_absolute_configuration ad
_chemical_compound_source        'Local laboratory'
_chemical_formula_moiety         'C19 H17 N O4 S '
_chemical_formula_sum            'C19 H17 N O4 S'
_chemical_formula_weight         355.412
_chemical_name_systematic
;
 ?
;
_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_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           maXus
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   6.49920(10)
_cell_length_b                   14.9706(4)
_cell_length_c                   34.8326(6)
_cell_measurement_reflns_used    5145
_cell_measurement_temperature    150
_cell_measurement_theta_max      24.108
_cell_measurement_theta_min      2.910
_cell_volume                     3389.10(12)
_computing_cell_refinement       'HKL Scalepack (Otwinowski & Minor 1997)'
_computing_data_collection       KappaCCD
_computing_data_reduction
'Denzo and Scalepak (Otwinowski & Minor, 1997)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution
'SIR97(Cascarano al.,Acta Cryst.,1996,A52,C-79)'
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device       KappaCCD
_diffrn_measurement_method       CCD
_diffrn_orient_matrix_type       X=UH
_diffrn_orient_matrix_UB_11      -0.14464
_diffrn_orient_matrix_UB_12      0.04231
_diffrn_orient_matrix_UB_13      0.03104
_diffrn_orient_matrix_UB_21      -0.02206
_diffrn_orient_matrix_UB_22      -0.05886
_diffrn_orient_matrix_UB_23      -0.02258
_diffrn_orient_matrix_UB_31      0.00232
_diffrn_orient_matrix_UB_32      -0.01100
_diffrn_orient_matrix_UB_33      0.02642
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           ' MoK\a'
_diffrn_radiation_wavelength_id  all
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       40
_diffrn_reflns_limit_l_min       -39
_diffrn_reflns_number            8897
_diffrn_reflns_theta_full        24.12
_diffrn_reflns_theta_max         24.12
_diffrn_reflns_theta_min         2.92
_exptl_absorpt_coefficient_mu    0.215
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.393
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       Prisms
_exptl_crystal_F_000             1488
_exptl_crystal_size_max          0.031
_exptl_crystal_size_mid          0.010
_exptl_crystal_size_min          0.005
_refine_diff_density_max         0.750
_refine_diff_density_min         -0.350
_refine_diff_density_rms         0.086
_refine_ls_abs_structure_details 'Flack (1983), from 2227 Friedels'
_refine_ls_abs_structure_Flack   0.05(12)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.198
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     451
_refine_ls_number_reflns         5330
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.198
_refine_ls_R_factor_all          0.0665
_refine_ls_R_factor_gt           0.0567
_refine_ls_shift/su_max          0.00
_refine_ls_shift/su_mean         0.00
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0689P)^2^+3.2504P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1444
_refine_ls_wR_factor_ref         0.1601
_reflns_number_gt                4809
_reflns_number_total             5330
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol047528jsi20041202_103114.cif
_cod_data_source_block           global
_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_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21 21 21    '
_cod_original_formula_sum        'C19 H17 N O4 S '
_cod_database_code               1506466