Synthesis of a biofuel target through conventional organic chemistry

Page, Jordan P.; Robinson, Joshua W.; Albrecht, Karl O.; Cosimbescu, Lelia

doi:10.1016/j.tetlet.2018.02.073

Synthesis of a biofuel target through conventional organic chemistry

Journal Article · Wed Feb 28 00:00:00 EST 2018 · Tetrahedron Letters

DOI:https://doi.org/10.1016/j.tetlet.2018.02.073· OSTI ID:1423329

Page, Jordan P. ^[1]; Robinson, Joshua W. ^[1]; Albrecht, Karl O. ^[1]; Cosimbescu, Lelia ^[1]

Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Energy and Environment Directorate

Here in this work, the biofuel target compound 2-ethyl-5,5-dimethylcyclopenta-1,3-diene (1) and its exo isomers (9a and 9b), were successfully synthesized via two different pathways from the common intermediate 4,4-dimethylcyclopent-2-ene-1-one (2). The first pathway produced the endocyclic product as a pure isomer via a triflate intermediate obtained from ketone 2 in 60% yield, followed by copper-catalyzed coupling with ethyl magnesium bromide in 63% yield. The second pathway employed a Grignard reaction with ketone 2, which generated an alcohol that was immediately subjected to mild acid-catalyzed elimination to yield primarily a mixture of exo isomers 9a and 9b in 46% yield. The preparation method developed by this work allowed for the production of a sufficient quantity of these targets to evaluate their fuel properties, which will be reported in a separate study.

Research Organization:: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States)

Sponsoring Organization:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Bioenergy Technologies Office (EE-3B); USDOE Office of Energy Efficiency and Renewable Energy (EERE), Vehicle Technologies Office (EE-3V)