Date of Graduation

Summer 2017


Master of Science in Chemistry


Chemistry and Biochemistry

Committee Chair

Matthew Siebert


Propargylic acetates can lead to complex transformations upon exposure to a gold catalyst. Gold catalyzed transformations also allow for simple synthesis of a number of natural products. Gold (III)-cycloisomerization of a 5-acetoxy-1,6-enyne is reported to proceed through two pathways that differ in the order of major events: cyclization followed by ester migration (“cyclization first”) or the reverse (“migration first”). Both pathways could theoretically proceed in either order. This rearrangement is called the Ohloff-Rautenstrauch rearrangement and has high regio- and stereocontrol affording a bicylo[4.1.0]heptane carbon substructure. This rearrangement allows for the synthesis of the carene class of natural products. Computational modeling determining the mechanism and preference for the pathways in the gas- and solvent-phase (dichloroethane, IEFPCM) are described herein. Structures for the pathways are found using the B2PLYP/6-31G(d)-LANL2DZ model chemistry while energies are found at the B2PLYP-D3/def2TZVP//B2PLYP/6-31G(d)-LANL2DZ level. Both pathways feature multiple steps with low energy barriers. Highest-energy structures for both pathways are close in energy (ΔΔE‡ = 2.8 kcal/mol for solvent phase). Turnover frequency for each pathway are calculated suggesting that the cyclization first pathway may dominate.


DFT, gold (III), propargylic acetate, carene, natural products

Subject Categories

Organic Chemistry | Physical Chemistry


© Jeremy M. Hines

Open Access