Burkhart B M, Papchikhin A, Chattopadhyaya J, Sundaralingam M
Department of Chemistry, Ohio State Univeristy, Columbus 43210, USA.
Acta Crystallogr C. 1995 Jul 15;51 ( Pt 7):1462-4. doi: 10.1107/s0108270194014332.
The title compound, C15H21N3O7, is a thymidine derivative with a tetrahydroisoxazole (THI) ring fused to the sugar ring at the 2'- and 3'-C atoms. The thymine base is in an anti conformation [chi = -122.5 (3) degrees] while the ribose moiety has C2'-exo,C3'-endo (3T2) conformation with a highly flattened sugar ring [P = -5.8, tau m = 13.1 degrees]. The molecule contains a pseudo-twofold axis on the C2'-C3' bond with the ethyl ester group acting as the base and the N-methyl group acting as the 5'-hydroxyl group in a nucleoside. The THI ring fused to the furanose has a C3'-endo,C4'-exo (3T4) conformation [P = 4.18, tau m = 19.3 degrees]. The ethyl ester moiety is disordered with respect to two conformations, the population of the major form being 87.4 (8)% and that of the minor form 12.6 (8)%.
标题化合物C15H21N3O7是一种胸腺嘧啶核苷衍生物，其在2'-和3'-C原子处有一个与糖环稠合的四氢异恶唑（THI）环。胸腺嘧啶碱基呈反式构象[χ = -122.5 (3)°]，而核糖部分具有C2'-外，C3'-内（3T2）构象，糖环高度扁平[P = -5.8，τm = 13.1°]。该分子在C2'-C3'键上有一个伪二重轴，乙酯基团充当碱基，N-甲基基团充当核苷中的5'-羟基。与呋喃糖稠合的THI环具有C3'-内，C4'-外（3T4）构象[P = 4.18，τm = 19.3°]。乙酯部分相对于两种构象无序，主要构象的占有率为87.4 (8)%，次要构象的占有率为12.6 (8)%。
