Purine nucleoside antibiotics: recent synthetic advances harnessing chemistry and biology.

Covering: 2019 to 2023Nucleoside analogues represent one of the most important classes of small molecule pharmaceuticals and their therapeutic development is successfully established within oncology and for the treatment of viral infections. However, there are currently no nucleoside analogues in clinical use for the management of bacterial infections. Despite this, a significant number of clinically recognised nucleoside analogues are known to possess some antibiotic activity, thereby establishing a potential source for new therapeutic discovery in this area. Furthermore, given the rise in antibiotic resistance, the discovery of new clinical candidates remains an urgent global priority and natural product-derived nucleoside analogues may also present a rich source of discovery space for new modalities. This Highlight, covering work published from 2019 to 2023, presents a current perspective surrounding the synthesis of natural purine nucleoside antibiotics. By amalgamating recent efforts from synthetic chemistry with advances in biosynthetic understanding and the use of recombinant enzymes, prospects towards different structural classes of purines are detailed.

Synthesis of 1-Deoxymannojirimycin from d-Fructose using the Mitsunobu Reaction.

Three different Mitsunobu reactions have been investigated for the synthesis of 1-deoxymannojirimycin (1-DMJ) from d-fructose. The highest yielding and most practical synthesis can be undertaken on a 10 g scale with minimal chromatography. In the key step, N,O-di-Boc-hydroxylamine reacts with methyl 1,3-isopropylidene-α-d-fructofuranose under Mitsunobu conditions to give 14. Acidic hydrolysis affords nitrone 15, which reduces quantitatively via catalytic hydrogenolysis to afford 1-DMJ (4) in 55% overall yield from d-fructose (cf. 37% for azide route and 29% for nosyl route).