Approach to the synthesis of herbicidins.
Item
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Title
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Approach to the synthesis of herbicidins.
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Identifier
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AAI9405517
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identifier
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9405517
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Creator
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Das, Kajal Kanti.
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Contributor
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Adviser: Vernon G. S. Box
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Date
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1993
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemistry, Organic
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Abstract
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The Herbicidins are structurally intriguing antibiotics which show remarkable biological activity. We have tried to develop a synthetic route to these antibiotics, based on the use of glucose as a chiral synthon, because the structures of these molecules can be regarded as being composed of glucose derived units.;The retrosynthetic plan called for the construction of one half of the Herbicidin molecule from a D-glucofuranosidic unit which would be converted into a suitable 6-deoxy-6-iodo-D-glucofuranoside. The other half of the Herbicidin molecule would be derived from a D-glucopyranosidic unit which would be transformed into a 3,6-anhydro-D-glucopyranoside and thence to the target synthon.;The pivalate ester was extensively used for the protection of hydroxyl groups and several interesting selective esterification reactions were encountered. The unusual migration of the pivalate group from C-2 to C-1 was also encountered during a hydrolysis of a 3,6-anhydro-D-glucopyranoside, and this reaction was of significant mechanistic interest.;The pivalate ester group was utilized in a number of synthetic intermediates, primarily because of its relatively low migratory aptitude, to its adjacent carbon atom, via the formation of highly crowded cyclic and neopentyl type intermediate. From our esterification reactions we were able to determine the relative reactivities of the hydroxyl groups of 4,6-O-anisylidene-D-glucopyranose and its derivatives.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
