Synthesis of bi- and tricyclic analogues of myo-inositol 3,4,5,6- and 1,4,5,6-tetrakisphosphate with extended carbon backbone

myo-Inositol 3,4,5,6-tetrakisphosphate [Ins(3,4,5,6)P4] and its enantiomer exhibit distinct functions in the regulation of transepithelial chloride secretion. In search for agonists and antagonists of these potential messengers we synthesized a bicyclic oxepin analogue and a tricyclic analogue with a selfprotecting dioxolane moiety. The carbon backbone extension was linked to the C2 position. Ring closure was achieved by a metathesis reaction.