The present invention provides a new labeling reagent for preparing modified oligonucleotides and processes for their production wherein these oligonucleotides contain at least once the structure P═N—SO
2
-benzole-L-M-X, characterized in that L is either —(CH
2
)n- or polyethylene glycol, M is selected from a group consisting of —NH—, —O—, —S—, and —COO—, and X is either a protecting group or a detectable unit. L is preferably either —(CH
2
)n- or polyethylene glycol.
Synthesis of diastereomerically pure 1,4,5-substituted-2-oxopiperazines on solid-phase
作者:Nawaz M Khan、Montserrat Cano、Shankar Balasubramanian
DOI:10.1016/s0040-4039(02)00268-x
日期:2002.3
5-substituted-2-oxopiperazines are reported. The synthetic strategy is based on reductive alkylation of resin-bound amino acids using N-protected α-amino aldehydes (with concomitant epimerization), followed by acylation with α-chloroacetyl chloride. Subsequent stereoselective on-bead intramolecular cyclization has led to a diastereomerically pure 2-oxopiperazine.