Synthesis of l-Deoxyribonucleosides from d-Ribose

J Org Chem. 2018 Dec 21;83(24):14923-14932. doi: 10.1021/acs.joc.8b02002. Epub 2018 Nov 29.

Abstract

The preparation of 2-deoxy-l-ribose derivatives or mirror image deoxyribonucleosides (l-deoxyribonucleosides) from d-ribose is reported. Starting from inexpensive d-ribose, an acyclic d-form carbohydrate precursor was synthesized to study a unique carbonyl translocation process. In this novel radical reaction, not only was the configuration of the sugar transformed from the d-form to the l-form, but also deoxygenation at the C(2) position of the sugar was successfully achieved. This is one of the most practical methods for converting a d-sugar to a 2-deoxy-l-sugar in a one-step reaction. To further identify the reaction product, radical reactions followed by treatment with 1,3-propanedithiol and then benzoylation were performed to afford a dithioacetal derivative. The stereochemistry and configuration of the 2-deoxy-l-ribose dithioacetal derivative were confirmed by its X-ray crystal structure. To further apply this methodology, a diethyl thioacetal derivative was formed, followed by selective benzoyl protection, and an NIS-initiated cyclization reaction to give the desired ethyl S-l-2-deoxyriboside, which can be used as a 2-deoxy-l-ribosyl synthon in the formal total synthesis of various l-deoxyribonucleosides, such as l-dT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chemistry Techniques, Synthetic
  • Cyclization
  • Deoxyribonucleosides / chemical synthesis*
  • Deoxyribonucleosides / chemistry*
  • Ribose / chemistry*
  • Stereoisomerism

Substances

  • Deoxyribonucleosides
  • Ribose