The first synthesis of herbicidin B, a tricyclic-sugar adenine nucleoside antibiotic, using samarium diiodide-promoted aldol-type C-glycosidation reaction as a key-step.

A first total synthesis of the nucleoside antibiotic herbicidin B (1) was achieved in which a novel aldol-type C-glycosidation reaction promoted by samarium diiodide (SmI2) was used as a key step. Construction of the desired stereochemistry of the tricyclic-sugar moiety was successfully achieved by conformational restriction strategy based on repulsion between adjacent bulky protecting groups on the pyranose ring.