C,O-Dialkylation of Meldrum's Acid: Synthesis and Reactivity of 1,3,7,7-Tetramethyl-4H,10H-6,8,9-trioxa-2-thiabenz[f]azulen-5-one
Chad A. Snyder; John P. Selegue; Eniolami Dosunmu; Nathan C. Tice; Sean Parkin; Journal of Organic Chemistry 68 (2003) 7455–7459; doi:10.1021/jo034708i

data_4022505
_publ_section_title
;
 C,O-Dialkylation of Meldrum's Acid: Synthesis and Reactivity of
 1,3,7,7-Tetramethyl-4H,10H-6,8,9-trioxa-2-thiabenz[f]azulen-5-one
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              7455
_journal_page_last               7459
_journal_paper_doi               10.1021/jo034708i
_journal_volume                  68
_journal_year                    2003
_chemical_formula_moiety         'C15 H20 O4 S'
_chemical_formula_sum            'C15 H20 O4 S'
_chemical_formula_weight         296.37
_chemical_melting_point          404.6(5)
_chemical_name_systematic
; 
1,3-dimethyl-6-oxo-7,8-dihydro-4H,6H-
thieno[3,4-c]oxepine-7-carboxylic acid tert-butyl ester 
;
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_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
_cell_angle_alpha                90.00
_cell_angle_beta                 99.350(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   23.1010(5)
_cell_length_b                   5.8010(2)
_cell_length_c                   11.3580(10)
_cell_measurement_reflns_used    55708
_cell_measurement_temperature    90.0(2)
_cell_measurement_theta_max      25.35
_cell_measurement_theta_min      1.00
_cell_volume                     1501.85(15)
_computing_cell_refinement       'SCALEPACK (Otwinowski & Minor, 1997)'
_computing_data_collection       'COLLECT (Nonius, 1998)'
_computing_data_reduction        'DENZO-SMN (Otwinowski & Minor, 1997)'
_computing_molecular_graphics    'XP in Siemens SHELXTL (Sheldrick, 1994)'
_computing_publication_material
;
SHELX97-2 (Sheldrick, 1997) and local procedures
;
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      90.0(2)
_diffrn_detector_area_resol_mean 18
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Nonius KappaCCD diffractometer'
_diffrn_measurement_method       '\w scans at fixed \c = 55\%'
_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  0.0594
_diffrn_reflns_av_sigmaI/netI    0.0870
_diffrn_reflns_limit_h_max       27
_diffrn_reflns_limit_h_min       -27
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -6
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            4979
_diffrn_reflns_theta_full        25.00
_diffrn_reflns_theta_max         25.00
_diffrn_reflns_theta_min         1.79
_diffrn_standards_decay_%        <1
_exptl_absorpt_coefficient_mu    0.226
_exptl_absorpt_correction_T_max  0.9955
_exptl_absorpt_correction_T_min  0.9152
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Scalepack (Otwinowski & Minor, 1997)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.311
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'thin plate'
_exptl_crystal_F_000             632
_exptl_crystal_size_max          0.40
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.02
_refine_diff_density_max         .296
_refine_diff_density_min         -.272
_refine_diff_density_rms         .060
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.225
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     186
_refine_ls_number_reflns         2633
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.225
_refine_ls_R_factor_all          0.1070
_refine_ls_R_factor_gt           0.0810
_refine_ls_shift/su_max          0.032
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0344P)^2^+0.9350P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1195
_refine_ls_wR_factor_ref         0.1265
_reflns_number_gt                2123
_reflns_number_total             2633
_reflns_threshold_expression     >2\s(I)
_cod_data_source_file            jo034708isi20030522_123330.cif
_cod_data_source_block           k02136
_cod_depositor_comments
;
The following automatic conversions were performed:

'_chemical_melting_point' value '131-132 deg C' was changed to
'404.6(5)' - it was converted from degrees Celsius(C) to Kelvins(K),
the average value was taken and precision was estimated.

Automatic conversion script
Id: cif_fix_values 1646 2011-03-28 12:23:43Z adriana 
;
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4022505