(3<i>R</i>,4<i>S</i>,4a<i>R</i>,10a<i>S</i>)-5,10-Diacetyl-3,4,4a,5,6,7,10,10a-octahydro-8-methoxy-6-oxo-2<i>H</i>-pyrano[3,2-<i>g</i>]pteridin-3,4-diyl diacetate
Low, John N.; M. Dolores López; M. Luisa Quijano; Sánchez, Adolfo; Nogueras, Manuel; Acta Crystallographica Section C 55 (1999) 452–454; doi:10.1107/S0108270198014371

data_2008302
_publ_section_title
;(3<i>R</i>,4<i>S</i>,4a<i>R</i>,10a<i>S</i>)-5,10-Diacetyl-3,4,4a,5,6,7,10,10a-octahydro-8-methoxy-6-oxo-2<i>H</i>-pyrano[3,2-<i>g</i>]pteridin-3,4-diyl
 diacetate
;
_journal_issue                   3
_journal_name_full               'Acta Crystallographica Section C'
_journal_page_first              452
_journal_page_last               454
_journal_paper_doi               10.1107/S0108270198014371
_journal_volume                  55
_journal_year                    1999
_chemical_formula_moiety         'C18 H22 N4 O9'
_chemical_formula_sum            'C18 H22 N4 O9'
_chemical_formula_weight         438.40
_chemical_name_systematic
;
[(3R,4S,4aR,10aS)-5,10-diacetyl-3,4,4a,5,6,7,10a,10-octahydro-8-methoxy-6-oxo
-2H-pyrano[3,2g]pteridin]-3,4-diyl diacetate
;
_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'
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.941(3)
_cell_length_b                   17.481(2)
_cell_length_c                   14.511(3)
_cell_measurement_reflns_used    250
_cell_measurement_temperature    294.0(10)
_cell_measurement_theta_max      25.03
_cell_measurement_theta_min      1.82
_cell_volume                     2014.4(9)
_computing_cell_refinement       'CAD-4-PC and FAST/MADNES'
_computing_data_collection
;CAD-4-PC (Enraf-Nonius, 1992) and FAST/MADNES (Pflugrath & Messerschmidt,
 1980)
;
_computing_data_reduction
'CAD-4-PC, FAST/MADNES and DATRD2 in NRCVAX94 (Gabe et al., 1989)'
_computing_molecular_graphics
'ORTEPII (Johnson, 1976) and PLATON (Spek, 1998)'
_computing_publication_material
'NRCVAX96, SHELXL97  and PREP8 (Ferguson, 1998)'
_computing_structure_refinement  'NRCVAX96 and SHELXL97 (Sheldrick, 1997a)'
_computing_structure_solution    'SHELXS97 (Sheldrick, 1997b)'
_diffrn_ambient_temperature      294.0(10)
_diffrn_measured_fraction_theta_full 0.872
_diffrn_measured_fraction_theta_max 0.872
_diffrn_measurement_device
;
Enraf-Nonius diffractometer with FAST area-detector
;
_diffrn_measurement_method
'MADNES scans (Pflugrath & Messerschmidt, 1980)'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'X-ray tube'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.098
_diffrn_reflns_av_sigmaI/netI    0.106
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            8231
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         1.82
_diffrn_standards_decay_%        'as above'
_diffrn_standards_interval_time  'as above'
_diffrn_standards_number         'Not applicable - FAST data'
_exptl_absorpt_coefficient_mu    0.117
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.446
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             920
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.14
_refine_diff_density_max         0.323
_refine_diff_density_min         -0.256
_refine_ls_abs_structure_details 'Flack (1983), 1091 Friedel pairs'
_refine_ls_abs_structure_Flack   -5.8(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.837
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     285
_refine_ls_number_reflns         2893
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.837
_refine_ls_R_factor_all          0.054
_refine_ls_R_factor_gt           0.039
_refine_ls_shift/su_max          <0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0249P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.084
_reflns_number_gt                2076
_reflns_number_total             2893
_reflns_threshold_expression     I>2\s(I)
_cod_data_source_file            sk1253.cif
_cod_data_source_block           sp49
_cod_database_code               2008302
_cod_database_fobs_code          2008302