Modular Synthesis of Constrained Ethyl (cEt) Purine and Pyrimidine Nucleosides.
Blade, Helen; Bradley, Derek; Diorazio, Louis; Evans, Timothy; Hayter, Barry R.; Howell, Gareth P.; The Journal of organic chemistry 80 (2015) 5337–5343; doi:10.1021/acs.joc.5b00607

data_4036211
_publ_section_title
;
 Modular Synthesis of Constrained Ethyl (cEt) Purine and Pyrimidine
 Nucleosides.
;
_journal_issue                   10
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              5337
_journal_page_last               5343
_journal_paper_doi               10.1021/acs.joc.5b00607
_journal_volume                  80
_journal_year                    2015
_chemical_formula_moiety         C14H22O8
_chemical_formula_sum            'C14 H22 O8'
_chemical_formula_weight         318.31
_chemical_melting_point          375.1
_chemical_name_common            'acetal, structure 15'
_chemical_name_systematic
;
(3aS,3bR,7aS,8aR)-7a-[(4R)-2,2-Dimethyl-1,3-dioxolan-4-yl]-2,2-dimethyltetrahydro
-3bH-[1,3]dioxolo[4,5]furo[3,2-d][1,3]dioxin-3b-ol
;
_space_group_crystal_system      triclinic
_space_group_IT_number           1
_space_group_name_Hall           'P 1'
_space_group_name_H-M_alt        'P 1'
_atom_sites_solution_hydrogens   geom
_cell_angle_alpha                106.18(2)
_cell_angle_beta                 100.896(19)
_cell_angle_gamma                96.42(2)
_cell_formula_units_Z            1
_cell_length_a                   6.098(4)
_cell_length_b                   7.378(5)
_cell_length_c                   9.239(5)
_cell_measurement_temperature    200.(2)
_cell_volume                     386.0(4)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      200.(2)
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0766
_diffrn_reflns_av_unetI/netI     0.1028
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       10
_diffrn_reflns_limit_l_min       -10
_diffrn_reflns_number            6381
_diffrn_reflns_theta_full        24.39
_diffrn_reflns_theta_max         24.39
_diffrn_reflns_theta_min         2.92
_exptl_absorpt_coefficient_mu    0.113
_exptl_absorpt_correction_T_max  0.9780
_exptl_absorpt_correction_T_min  0.9150
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS V2014/5 (Bruker AXS Inc.)'
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.369
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       rod
_exptl_crystal_F_000             170
_exptl_crystal_size_max          0.800
_exptl_crystal_size_mid          0.300
_exptl_crystal_size_min          0.200
_refine_diff_density_max         0.226
_refine_diff_density_min         -0.344
_refine_ls_abs_structure_details
;
Flack x determined using 595 quotients [(I+)-(I-)]/[(I+)+(I-)]
(Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.8(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.971
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     204
_refine_ls_number_reflns         2451
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      0.971
_refine_ls_R_factor_all          0.0848
_refine_ls_R_factor_gt           0.0607
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0835P)^2^+0.2016P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1485
_refine_ls_wR_factor_ref         0.1668
_reflns_number_gt                1832
_reflns_number_total             2451
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo5b00607_si_003.cif
_cod_data_source_block           I
_cod_database_code               4036211
_shelx_res_checksum              98581
_shelx_hkl_checksum              48221