Diastereo- and enantioselective synthesis of N,O-nucleosides
摘要:
The diastereo- and enantioselective synthesis of alpha- and beta-3'-hydroxymethyl-N,O-nucleosides is described, based on the 1,3-dipolar cycloaddition of a N-glycosyl nitrone. Two approaches have been evaluated: the one-step procedure, which uses vinyl nucleobases, showed a better stereoselectivity towards beta-nucleosides. (C) 2003 Elsevier Ltd. All rights reserved.
Homochiral α-d- and β-d-Isoxazolidinylthymidines via 1,3-Dipolar Cycloaddition
摘要:
The introduction of chiral auxiliaries at the C- or N-atom in starting nitrones has been investigated as a stereoselective synthetic route to heterocyclic nucleoside analogues. The carbohydrate auxiliary at nitrogen atom gave the best results, thus allowing an easy and enantioselective synthesis of isoxazolidinyl thymine 26.
The introduction of chiral auxiliaries at the C- or N-atom in starting nitrones has been investigated as a stereoselective synthetic route to heterocyclic nucleoside analogues. The carbohydrate auxiliary at nitrogen atom gave the best results, thus allowing an easy and enantioselective synthesis of isoxazolidinyl thymine 26.
Diastereo- and enantioselective synthesis of N,O-nucleosides
The diastereo- and enantioselective synthesis of alpha- and beta-3'-hydroxymethyl-N,O-nucleosides is described, based on the 1,3-dipolar cycloaddition of a N-glycosyl nitrone. Two approaches have been evaluated: the one-step procedure, which uses vinyl nucleobases, showed a better stereoselectivity towards beta-nucleosides. (C) 2003 Elsevier Ltd. All rights reserved.