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Conversions of beta-carotene and some related polyenes to keto and hydroxy derivatives by means of N-bromosuccinimide and boron trifluorides

Citation

Petracek, Francis James (1956) Conversions of beta-carotene and some related polyenes to keto and hydroxy derivatives by means of N-bromosuccinimide and boron trifluorides. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-06212004-154038

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. The reaction of N-bromosuccinimide (NBS) with [beta]-carotene in alcohol-containing chloroform results mainly in the formation of 4-keto-[beta]-carotene, 4,4'-diketo-[beta]-carotene, and 4-keto-3',4'-dehydro-[beta]-carotene, Their structures were clarified by relating them to known carotenoids through partial synthetic or degradative schemes. In the course of this work, the following new carotenoids were also prepared: 4-keto-4'-hydroxy-[beta]-carotene, 4,4'-dihydroxy-[beta]-carotene, 4-hydroxy-3',4'-dehydro-[beta]-carotene and 4-keto-[alpha]-carotene. A reaction mechanism for the conversion of carotenes to ketones is proposed, based on pertinent experiments. The infrared and visible spectra of the new compounds are discussed, and the provitamin A2 effect of the 3,4-dehydro compounds has been demonstrated. Synthetic 4,4'-diketo-[beta]-carotene has been identified with canthaxanthin occurring in some fungi and algae. The investigation of the products from the hydrolysis and ethanolysis of BF3-carotenoid complexes has been continued and extended: [beta]-carotene, [retro]-dehydrocarotene and 3,4-dehydro-[beta]-carotene have yielded 4-hydroxy-[beta]-carotene. From 3,4-dehydro-[alpha]-carotene 4-hydroxy-[alpha]-carotene was obtained. [retro]-Bisdehydrocarotene gave a new type of carotenoid, viz. 2-hydroxy-3,4-dehydro-[beta]-carotene. From anhydrovitamin A1 a new isomer of vitamin A1, viz. 4-hydroxy-axeropthene, was obtained. A photometric method for determining the partition coefficients of carotenoids was devised and tested on thirty-two compounds.

Item Type:Thesis (Dissertation (Ph.D.))
Degree Grantor:California Institute of Technology
Division:Chemistry and Chemical Engineering
Major Option:Chemistry
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Zechmeister, Laszlo
Thesis Committee:
  • Unknown, Unknown
Defense Date:1 January 1956
Record Number:CaltechETD:etd-06212004-154038
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-06212004-154038
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2667
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:22 Jun 2004
Last Modified:26 Dec 2012 02:53

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