Title

New Examples of Amine-Induced Reversal of Diasteroselectivity During Acylation of Trans-1,2-Substituted Cyclohexanols

Poster Number

55

Lead Author Major

Chemistry

Format

Poster Presentation

Faculty Mentor Name

Andreas Franz

Faculty Mentor Department

Chemistry

Additional Faculty Mentor Name

Vyacheslav V. Samoshin

Abstract/Artist Statement

A reaction between two racemic mixtures yields two diastereomers. The diastereoselective outcome of reactions in nature is dependent on a multitude of factors. Understanding the underlying mechanistic principles that govern these reactions is imperative if diastereoselective reactions are to be used not just in the laboratory but on an industrial scale. In this presentation, we report new results for amine-induced changes in diastereoselectivity during the acylation of (matched/mismatched) chiral templates. Racemic mixtures of trans-1,2-substituted cyclohexanols were reacted with 2-chloro propionyl chloride with or without an amine catalyst. The products were isolated and purified using column chromatography and analyzed using NMR spectroscopy. Additionally, computational methods were used to explore potential reaction pathways. The presence of simple achiral amines, such as pyridine and DMAP, during acylation of racemic trans-1,2-substituted cyclohexanols with racemic acylating agents appears to have significant influence on the diastereomeric ratio of the products and can even lead to reversal of diastereoselectivity.

Location

DeRosa University Center, Ballroom

Start Date

20-4-2013 1:00 PM

End Date

20-4-2013 3:00 PM

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Apr 20th, 1:00 PM Apr 20th, 3:00 PM

New Examples of Amine-Induced Reversal of Diasteroselectivity During Acylation of Trans-1,2-Substituted Cyclohexanols

DeRosa University Center, Ballroom

A reaction between two racemic mixtures yields two diastereomers. The diastereoselective outcome of reactions in nature is dependent on a multitude of factors. Understanding the underlying mechanistic principles that govern these reactions is imperative if diastereoselective reactions are to be used not just in the laboratory but on an industrial scale. In this presentation, we report new results for amine-induced changes in diastereoselectivity during the acylation of (matched/mismatched) chiral templates. Racemic mixtures of trans-1,2-substituted cyclohexanols were reacted with 2-chloro propionyl chloride with or without an amine catalyst. The products were isolated and purified using column chromatography and analyzed using NMR spectroscopy. Additionally, computational methods were used to explore potential reaction pathways. The presence of simple achiral amines, such as pyridine and DMAP, during acylation of racemic trans-1,2-substituted cyclohexanols with racemic acylating agents appears to have significant influence on the diastereomeric ratio of the products and can even lead to reversal of diastereoselectivity.