Alternative syntheses of (S)-cEt-BNA: a key constrained nucleoside component of bioactive antisense gapmer sequences

J Org Chem. 2014 Dec 5;79(23):11651-60. doi: 10.1021/jo502320y. Epub 2014 Nov 17.

Abstract

Approaches to the synthesis of the constrained 5-methyluracil nucleoside (S)-cEt-BNA, a key "gapmer" unit in a number of biologically relevant antisense oligonucleotides, are described using 5-methyluridine as starting material. In the shorter synthesis, a nine-step linear sequence afforded a O-protected (S)-cEt-BNA consisting of a [2.2.1]dioxabicycloheptane core in 7% overall yield. A competing reaction in an intramolecular cyclization of a tosylate led to a bicyclic oxetane.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bridged Bicyclo Compounds / chemical synthesis*
  • Bridged Bicyclo Compounds / chemistry*
  • Bridged-Ring Compounds / chemical synthesis
  • Cyclization
  • Ethers, Cyclic / chemical synthesis*
  • Ethers, Cyclic / chemistry*
  • Molecular Structure
  • Nucleosides / chemical synthesis
  • Oligonucleotides, Antisense / chemical synthesis
  • Thymine / chemical synthesis*
  • Thymine / chemistry*
  • Uridine / analogs & derivatives*
  • Uridine / chemistry*

Substances

  • Bridged Bicyclo Compounds
  • Bridged-Ring Compounds
  • Ethers, Cyclic
  • Nucleosides
  • Oligonucleotides, Antisense
  • oxetane
  • Thymine
  • Uridine