Diastereoselective synthesis of some carbocyclic 2 '-oxa-3 '-aza-nucleosides

作者：Hyrosova E^*; Fisera L; Jame R M A; Pronayova N; Medvecky M; Koos M

来源：Khimiya Geterotsiklicheskikh Soedinenii, 2007, (1): 14-21.

• chiral
• dipolar cycloadditions
• isoxazolidines
• modified nucleosides
• nitrones

Two strategies for the synthesis of isoxazolidinyl nucleosides as potential antiviral agents are reported: one-step approach based on 1,3-dipolar cycloaddition of D-lyxosyl nitrone with N,N-dibenzyl-9-vinyl adenine and two-step methodology based on the Vorbruggen nucleosidation of the 5-acetoxyisoxazolidine. The chiral D-lyxosyl nitrone undergoes regioselective 1,3-dipolar cycloadditions with N,N-dibenzyl-9-vinyl adenine and vinyl acetate giving 5-substituted isoxazolidines as a mixture of four diastereoisomers; in good yields. The condensation of 5-acetoxyisoxazolidine with silylated uracil, thymine, and N-acetylcytosine proceeded with moderate to good stereoselectivity under the formation of the expected isoxazolidinyl beta- and alpha-nucleosides.

• 出版日期2007-1