Font Size: a A A

I. Studies toward a phosphorus-based chiral auxiliary. II. N-tetrachlorophthaloyl (TCP) for ready protection/deprotection of amino sugar glycosides. III. Total synthesis of NodRf-III (C18:1)(MeFuc)

Posted on:1998-01-24Degree:Ph.DType:Thesis
University:Duke UniversityCandidate:Debenham, John SteeleFull Text:PDF
GTID:2461390014978898Subject:Chemistry
Abstract/Summary:
(I). Enantiomerically pure phospholanes have shown great promise as reagents for asymmetric synthesis. As such (2;(II). The tetrachlorophthaloyl (TCP) group can be utilized when imidic protection of an amine is desired and durability of the protecting group to conditions ranging from mildly basic to harshly acidic is required. Installation can be accomplished in two steps by treating the free base with the commercially available TCP anhydride and then closing the imidic ring with acetic anhydride and pyridine. Cleavage is effected by 2-4 eq. of ethylenediamine under very mild conditions under which esters and glycopeptides have been shown to be stable. Unsubstituted phthalimides, even within the same molecule, are also unaffected during TCP cleavage. TCP protecting groups serve as ;(III). A convergent stereocontrolled synthesis of the nodulation factor NodRf-III (C18:1, MeFuc) produced by Rhizobium fredii USDA257 has been achieved. Nodulation factors are lipooligosaccharides that are secreted by bacteria which trigger the early steps in the formation of root nodules in leguminous plants. This symbiotic relationship between plant and bacteria plays a major role in the global nitrogen cycle. Key to our synthetic approach was the use of the TCP (TetraChloroPhthaloyl) group to provide for N-differentiation of the linear glucosamine backbone and the use of FeCl...
Keywords/Search Tags:TCP, Synthesis
Related items
1 Green chemistry in pyrrole synthesis. I. Solvent effect in Barton-Zard pyrrole synthesis: An improved synthesis of 3,4-dialkyl-1H-pyrrole-2-carboxylates. II. A novel route for the synthesis of pharmaceutically important pyrrole derivatives
2 Part I: Design, synthesis, and reactivity of 1-hydrazinodienes for use in organic synthesis Part II: Studies toward a synthesis of the antibiotic platensimycin
3 Manganese(III)-based oxidative cyclizations: Formal synthesis of 15-acetoxypallescensin A. Synthesis of hindered guanidines. Completion of the total synthesis of martinellic acid
4 Synthesis, Characterization And Luminescence Properties Of Environmental Functional Material β-NaYF4 Doped With Rare Earth
5 Part I: The total synthesis of (+/-)-securinine and (+/-)-allosecurinine and synthetic strategies for a second generation synthesis of the securinega alkaloids and Part II: The use of (+)-K252a in the semi-synthesis of indolocarbazole natural products and
6 New methods and strategies for heterocycle synthesis: Progress toward the total synthesis of upenamide and the total synthesis of (+)-5-epiindolizidine 167B and indolizidine 223AB
7 Synthesis of side chain-modified iodothyronines. Synthesis and structure-activity relationships (SARS) of galanthamine derivatives. Total synthesis of (+)-valyldetoxinine. Synthesis and mechanism of cyclic acetal and ketal formation in pentono-1,4-lactone
8 The application of asymmetric catalysis to the synthesis of natural products: A total synthesis of (-)-tubulosine, progress towards a total synthesis of (+)-reserpine, and a total synthesis of (+)-peloruside A
9 Cyclobutanes in organic synthesis: Lewis acid-promoted ketene-alkene [2+2] cycloadditions, total synthesis of gracilioether F, and collaborative total synthesis of hippolachnin A
10 A ring-closing metathesis/Diels-Alder approach to the synthesis of the eunicellin diterpenes: Application to the total synthesis of ophirin B and partial synthesis of astrogorgin