Simple acyclic enynes can be easily converted into tricyclic ethers upon treatment with Co2(CO)8followed by Nicholas and Pauson−Khand reactions. Tricyclic [5,8,5]- and [5,7,5]-systems can be prepared in high overall yields in only seven synthetic steps.
“This document is the Accepted Manuscript version of a Published Work that appeared in final form in Organic Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see [insert ACS Articles on Request author-directed link to Published Work, see http://pubs.acs.org/doi/abs/10.1021/ol0479141
Quintal, Miriam M.; Closser, Kristina D.; and Shea, Kevin, "Tandem Intramolecular Nicholas and Pauson-Khand Reactions for the Synthesis of Tricyclic Oxygen-Containing Heterocycles" (2004). Chemistry: Faculty Publications. 10.