A Ring Closing Metathesis-Osmylation Approach to Oxygenated Oxepanes as Carbohydrate Surrogates.

Abstract A ring closing metathesis (RCM)-osmylation sequence has been developed for the formation of highly oxygenated cyclic ethers from the corresponding acyclic dienes. A systematic examination of various substrates in this reaction revealed that the process is general in scope and is insensitive to the number of alkoxy substituents present. Subsequent osmylation of the metathesis product proceeds with excellent diastereoselectivity to furnish highly oxygenated oxepanes. These oxepanes represent one-carbon homologated carbohydrates.