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Multistep Synthesis of a Betaxanthin Analogue and its Susceptibility to Nucleophilic Attack

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Title: Multistep Synthesis of a Betaxanthin Analogue and its Susceptibility to Nucleophilic Attack
Author: DeRosa, Louis
Advisor: Newirth, Terry
Department: Haverford College. Department of Chemistry
Type: Thesis (B.S.)
Issue Date: 2011
Abstract: Betanin is a naturally occurring glycoside found in beets, and is responsible for their characteristic red color. It is widely used as a coloring agent in foods such as ice cream, soda, and candy. As a natural food coloring, its sensitivity to pH, heat, oxygen, and light have all been studied. However, its sensitivity to nucleophiles has yet to be examined. This sensitivity is of interest because of the extended conjugated electrophilic π highway, which extends from the imminium ion of the upper ring to the nitrogen of the piperidine lower ring. The primary focus of our current research is in developing a multi-step synthesis of an analogue to betanin that conserves this extended chromophore and then testing this chromophore’s reactivity with thiols, a functional group found in many foods. This study discusses the successful development of the final condensation reaction between a previously synthesized betalamic acid analogue and proline using hexafluorophosphate as a stabilizing anion, and the purification of the product using High Performance Liquid Chromatography. This study also discusses NMR shift prediction and molecular orbital calculation evidence suggesting that the primary site of reaction between the synthesized analogue and the thiol 2-mercaptoethanol is either the middle carbon or the imine carbon of the conjugated chromophore.
Subject: Nucleophilic reactions
Subject: Betanin -- Synthesis
Terms of Use: http://creativecommons.org/licenses/by-nc/3.0/us/
Permanent URL: http://hdl.handle.net/10066/9377

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Citation

DeRosa, Louis. "Multistep Synthesis of a Betaxanthin Analogue and its Susceptibility to Nucleophilic Attack". 2011. Available electronically from http://hdl.handle.net/10066/9377.

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http://creativecommons.org/licenses/by-nc/3.0/us/ Except where otherwise noted, this item's license is described as http://creativecommons.org/licenses/by-nc/3.0/us/

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