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Type of Document	Dissertation
Author	Bush, Warren Van Ness
URN	etd-10072004-100851
Persistent URL	http://resolver.caltech.edu/CaltechETD:etd-10072004-100851
Title	A study of the boron trifluoride complexes of some carotenoid hydrocarbons and the products of their hydrolytic and alcoholytic cleavage
Degree	PhD
Option	Chemistry
Advisory Committee	Advisor Name Title L. Laszlo Zechmeister Committee Chair
Keywords	none
Date of Defense	1958-01-01
Availability	unrestricted
Abstract Formation of a deeply-colored [alpha]-carotene - boron trifluoride complex, by means of boron trifluoride etherate, and subsequent hydrolysis of the complex result mainly in the formation of 4-hydroxy-[alpha]-carotene, indicating that, under the conditions applied, only the [beta]-ionone end of the complex is reactive; ethanolysis gave the corresponding ethoxy derivative. The structures of these two compounds and some of the other reaction products were clarified. On this basis the structure of the BF3-complex has also been established, and a mechanism for its hydrolysis and alcoholysis was postulated. The length of the resonating system within the proposed complex is consistent with the observed deep blue color. Lycopene and [gamma]-carotene were studied along similar lines. The observed formation of 5,6-dihydroxy-5,6-dihydrolycopene by hydrolysis of the lycopene complex can be explained by means of a structure and a hydrolysis mechanism both similar to those of the [alpha]-carotene complex. The formation of 4-hydroxy-[gamma]-carotene by hydrolysis of the [gamma]-carotene complex is in accordance with an analogous structure and hydrolysis mechanism. The [beta]-ionone end of the [gamma]-carotene complex appears to be more reactive than the [psi]-ionone end. The cis-trans isomerization of 4-hydroxy-, 4-keto-, and 4-ethoxy-[alpha]-carotene as well as 5,6-dihydroxy-5,6-dihydrolycopene was studied.
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