De Novo Synthetic Route to a Combinatorial Library of Peptidyl Nucleosides
摘要:
A stereoselective synthetic route has been developed for the combinatorial synthesis of a structurally unique class of C-4' side chain modified peptide-linked nucleosides. The synthetic strategy and approach involves initial synthesis of a strategically functionalized amino butenolide template, utilizing L-serine as a chiral starting material. Subsequent transformation of the above lactone to C4' aminoalkyl substituted nucleosides, followed by the peptidic coupling of the C4' side chain amine with various amino acids completed the syntheses of the target peptidyl nucleosides. Employing the above route, and utilizing a combination of easily available nucleobases (4) and amino acids (6) as the two diversity elements, synthesis of a 24-member combinatorial library of the title peptide-linked nucleosides has been accomplished.
Trimethylsilyl Trifluoromethanesulfonate (TMSOTf) Assisted Facile Deprotection of N,O-Acetonides
摘要:
[GRAPHICS]Employing TMSOTf as an easily available reagent, we have developed a mild and efficient method for the deprotection of both terminal and internal NO-acetonide functionalities. Various regularly used protecting groups and common organic functional moieties were found to be unaffected by the described reaction conditions. In a few representative examples, the present method was also extended to deprotect acetonides obtained from 1,2-, and 1,3-terminal diols. The acetonide deprotection protocol described herein is expected to be a useful addition to the presently available methods for performing the above transformation.