From galactose to highly functionalized seven- and eight-membered carbocyclic rings by ring-closing metathesis

[GRAPHICS] A short synthesis of highly functionalized seven- and eight-membered carboc yclic rings from galactose derivatives has been achieved. the key steps are a zinc-mediated reductive ring opening of 6-iodogalactopyranoses and a sub sequent ring-closing olefin metathesis using Grubbs' ruthenium catalyst.