Imidazolidino[1,2-d]dithiadiazepines are converted to the ten-membered saturated heterocycles via borohydride reduction in acidic media or using "in situ" generated borane. Reductive alkylation in acetic or propionic acid as a solvent represents a significant side reaction. Relatively stable boron compounds are identified as intermediates which yield the saturated heterocycles upon acidic hydrolysis.
- borohydride reduction
- reaction mechanism