syn-trans Fused Bicyclic Ether Formation via Acetylene-biscobalthexacarbonyl Complex
Medium size bicyclic ethers of 7-, 8-, and 9-membered rings were synthesized by connection between a hydroxy group on dihydropyranyl ring and a propargylic cation that was stabilized as an acetylene biscobalthexacarbonyl complex under acidic conditions. This cyclization selectively afforded the <I>syn</I>-<I>trans</I> bicyclic ring system often seen in marine toxins such as ciguatoxin.
- Chemistry letters
Chemistry letters 1996(6), 473-474, 1996-06
The Chemical Society of Japan