Polyhydroxy-nortropanes

A common procedure used to forge carbocyclic systems is represented by the ring-closing metathesis reactions exploiting various Grubbs-type carbene catalysts. Based on this cyclization technology, Skaanderup and Madsen [71], on the way to polyhydroxy-nortropane calystegines, reported the asymmetric synthesis of aminated 6a-carbahexoseptanose derivatives 311. 

In the late 1980s a French group interested in the identification of metabolites produced by plant roots that might act as nutritional mediators of specific plant-bacterium relationships discovered the first nortropane-type polyhydroxy alkaloids... 

Through these methods, 26 calystegines, calystegine-like nortropanes, and calystegine glycosides were isolated to date (Table II). The isolation methods for polyhydroxy alkaloids appear laborious and tedious. However, alternative... 

---