Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for subject:(chromanones). Showing records 1 – 3 of 3 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


University of Edinburgh

1. Chandler, Ian Michael. Synthetic and biosynthetic studies on the polyketide metabolites LL-D253β and averufin.

Degree: PhD, 1987, University of Edinburgh

In Chapter 1 a brief outline of the range of naturally-occurring oxygen heterocycles is presented. This is follow ed by a com prehensive review of non-flavanoid naturally-occurring chromanones, including reference to any im portant biosynthetic studies. This is follow ed by a review of the synthesis of such compounds, concentrating on more recent developments Chapter 2 concerns the biosynthesis of the chrom anone LL-D253a, a metabolite of P. p ig m e ntivora . A review of previous studies is presented, followed by a brief account of the existence of the phenonium ion, though t to be an intermediate in the biosynthesis of LL-D253a. The incorporation of sodium [2 - 2H3,13C]-acetate, and of diethyl [ 2 - 13C]-malonate, into LL-D253a give an insight into the mechanism of its form ation. Chemical manipulation of deuterium labelled LL-D253a derivatives has supported the existence of a "phenonium'' intermediate. Chemical synthesis of some postulated prrecursors to Ll-D253a was undertaken. Chapter 3 concerns the biosynthesis of averufin, known to be a precursor to aflatoxin B-|. An overview of aflatoxin biosynthesis is presented, and includes a detailed review of relevant studies reported since 1980. The incorporation of [ 2 - 2H2]-hexanoic acid, and of diethyl [ 2 - 13C]-malonate, into averufin is reported. These results confirm that averufin is a decaketide, but during its biosynthesis it is able to exchange with endogenous hexanoate. Attem pted chemical manipulation of averufin, and incorporation of [7 - 2H2]-averufin into aflatoxin B-, is discussed.

Subjects/Keywords: 572; Biosynthesis of chromanones

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Chandler, I. M. (1987). Synthetic and biosynthetic studies on the polyketide metabolites LL-D253β and averufin. (Doctoral Dissertation). University of Edinburgh. Retrieved from http://hdl.handle.net/1842/27780

Chicago Manual of Style (16th Edition):

Chandler, Ian Michael. “Synthetic and biosynthetic studies on the polyketide metabolites LL-D253β and averufin.” 1987. Doctoral Dissertation, University of Edinburgh. Accessed September 23, 2020. http://hdl.handle.net/1842/27780.

MLA Handbook (7th Edition):

Chandler, Ian Michael. “Synthetic and biosynthetic studies on the polyketide metabolites LL-D253β and averufin.” 1987. Web. 23 Sep 2020.

Vancouver:

Chandler IM. Synthetic and biosynthetic studies on the polyketide metabolites LL-D253β and averufin. [Internet] [Doctoral dissertation]. University of Edinburgh; 1987. [cited 2020 Sep 23]. Available from: http://hdl.handle.net/1842/27780.

Council of Science Editors:

Chandler IM. Synthetic and biosynthetic studies on the polyketide metabolites LL-D253β and averufin. [Doctoral Dissertation]. University of Edinburgh; 1987. Available from: http://hdl.handle.net/1842/27780

2. Sneha Jose E; Dr. Mohanan P V. 2-Methoxy-4-chromanone ligated transition metal complexes.

Degree: 2019, Cochin University of Science and Technology

Subjects/Keywords: Chromones; 2-methoxy-4- chromanones - Antimicrobial screening; 2-methoxy-4- chromanones - DNA Binding

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

V, S. J. E. D. M. P. (2019). 2-Methoxy-4-chromanone ligated transition metal complexes. (Thesis). Cochin University of Science and Technology. Retrieved from http://dyuthi.cusat.ac.in/purl/5500

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

V, Sneha Jose E; Dr. Mohanan P. “2-Methoxy-4-chromanone ligated transition metal complexes.” 2019. Thesis, Cochin University of Science and Technology. Accessed September 23, 2020. http://dyuthi.cusat.ac.in/purl/5500.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

V, Sneha Jose E; Dr. Mohanan P. “2-Methoxy-4-chromanone ligated transition metal complexes.” 2019. Web. 23 Sep 2020.

Vancouver:

V SJEDMP. 2-Methoxy-4-chromanone ligated transition metal complexes. [Internet] [Thesis]. Cochin University of Science and Technology; 2019. [cited 2020 Sep 23]. Available from: http://dyuthi.cusat.ac.in/purl/5500.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

V SJEDMP. 2-Methoxy-4-chromanone ligated transition metal complexes. [Thesis]. Cochin University of Science and Technology; 2019. Available from: http://dyuthi.cusat.ac.in/purl/5500

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

3. Baldwin, Andrea Michelle. Synthesis and Functionalization of Heterocycles via Non-Covalent Catalysis.

Degree: PhD, Chemistry, 2016, The Ohio State University

Hydrogen-bond donor (HBD) catalysis has emerged as a remarkable platform for the activation of reactants through non-covalent interactions. This class of organocatalysts provides a sustainable alternative to transition metal catalysis and avoids the difficulties associated with trace metal removal. Classically, HBD catalyst interactions proceed in two major pathways: direct activation or anion recognition. Enhanced HBD catalysts that display improved performance under both modes of action allow for the discovery of new reactivity patterns that have previously been unattainable. Two new classes of elegantly designed non-covalent catalysts have been explored in the synthesis and functionalization of heterocycles.Boronate ureas, an internal Lewis acid assisted urea, are particularly well suited for the direct activation of molecules containing nitro-functionality. Donor-acceptor cyclopropanes are useful building blocks in synthetic chemistry due to the electronic nature of the strained ring and the intrinsic functionality. Boronate ureas were applied toward development of the first cycloaddition of nitrones with nitrocyclopropane carboxylates in the presence of an enhanced non-covalent catalyst. The highly functionalized 1,2-oxazinane core synthesized in this single step is a prominent scaffold in many bioactive targets. With this strategy, a small library of oxazinane products has been synthesized in up to 99% yield and 4:1 dr. A second class of enhanced catalysts, silanediols, have a propensity to recognize the ether functionality. This molecular recognition was exploited in the context of direct epoxide activation for carbon dioxide fixation. Typically, with organocatalytic cyclic carbonate formation, very few types of functional groups are able to affect this transformation under mild conditions; often, high temperatures, long reaction times, and high pressures of carbon dioxide are necessary for desired product formation. With only 10 mol % of a silanediol-tetrabutylammonium iodide co-catalyst system, this transformation can be accomplished at room temperature using only one bar of carbon dioxide.Having established the ability of silanediols to work in tandem with anions, chiral silanediols were investigated in enantioselective anion-binding catalysis to construct chromanones. To date, introduction of carbonyl-containing nucleophiles in an intermolecular fashion has only been performed racemically. However, the unique chemical environment accessible with novel chiral silanediols is able to control carbon-carbon bond formation between silyl ketene acetals and benzopyrylium salts generated in situ from chromone derivatives. When coupled with recrystallization, synthetically useful enantioselectivities of up to 74% can be obtained. Importantly, this is the first example of anion-binding catalysis utilizing the benzopyrylium ions of chromenones, as well as an innovative strategy to incorporate complex alkyl functionality directly into the scaffold of chromanones. Advisors/Committee Members: Mattson, Anita (Advisor).

Subjects/Keywords: Organic Chemistry; organocatalysis; hydrogen bond donor catalysis; silanediols; boronate ureas; oxazinanes; carbonates; chromanones; asymmetric catalysis

…93 3.2.2 Enantioselective Strategies Toward Chromanones… …97 3.2.3 Racemic Strategies Toward Complex Chromanones… …99 3.3 Enantioselective Silanediol-Catalyzed Synthesis of Chromanones… …123 3.5.6 General Procedure for Synthesis and Characterization of Chromanones....... 127… …136 3.5.9 HPLC Traces of Novel Chromanones… 

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Baldwin, A. M. (2016). Synthesis and Functionalization of Heterocycles via Non-Covalent Catalysis. (Doctoral Dissertation). The Ohio State University. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=osu1467277822

Chicago Manual of Style (16th Edition):

Baldwin, Andrea Michelle. “Synthesis and Functionalization of Heterocycles via Non-Covalent Catalysis.” 2016. Doctoral Dissertation, The Ohio State University. Accessed September 23, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=osu1467277822.

MLA Handbook (7th Edition):

Baldwin, Andrea Michelle. “Synthesis and Functionalization of Heterocycles via Non-Covalent Catalysis.” 2016. Web. 23 Sep 2020.

Vancouver:

Baldwin AM. Synthesis and Functionalization of Heterocycles via Non-Covalent Catalysis. [Internet] [Doctoral dissertation]. The Ohio State University; 2016. [cited 2020 Sep 23]. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1467277822.

Council of Science Editors:

Baldwin AM. Synthesis and Functionalization of Heterocycles via Non-Covalent Catalysis. [Doctoral Dissertation]. The Ohio State University; 2016. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=osu1467277822

.