title: Tandem enyne metathesis and claisen rearrangement: a versatile approach to conjugated dienes of variable substitution patterns.
abstract: To extend the versatility of the ruthenium carbene-promoted enyne metathesis, it was combined with an Ireland ester enolate Claisen rearrangement. This reaction sequence provided conjugated dienes of higher substitution pattern than that obtained through a cross-enyne metathesis alone. The Ireland-Claisen was conducted across both acyclic and cyclic dienes produced from cross-metathesis and methylene-free enyne metathesis, respectively. In the case of cyclodienes, the Ireland-Claisen rearrangement produced s-trans locked dienes which underwent mode-selective ene reaction. The tandem, sequential use of the Ireland-Claisen rearrangement also proved suitable for chirality transfer originating from chiral propargylic alcohols. Last, the tandem metathesis/Ireland-Claisen was utilized to access 4-substituted-3,5-cyclohexadiene diol derivatives, which are valuable chiral intermediates for natural product synthesis. The combination of this pericyclic reaction with a catalytic metathesis reaction extends the versatility of cross-metathesis since additional diene motifs can be accessed.
authors.affiliation: Department of Chemistry, University at Buffalo, the State University of New York, Buffalo, New York 14260-3000, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Clark
authors.forename: Amol A
authors.initials: AA
authors.lastname: Kulkarni
authors.forename: Kyle
authors.initials: K
authors.lastname: Kalbarczyk
authors.forename: Bryan
authors.initials: B
authors.lastname: Schertzer
authors.forename: Steven T
authors.initials: ST
authors.lastname: Diver