Spelling suggestions: "subject:"ring informationation (astrochemistry)"" "subject:"ring informationation (semiochemistry)""
71 |
Studies toward the total synthesis of (+)-cortistatin J via an intramolecular (4+3) cycloadditionLiu, Lok-lok., 廖樂樂. January 2011 (has links)
published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy
|
72 |
Transition metal and organo-catalyzed cyclizations, cycloadditions and couplingsCauble, David Frederic 28 August 2008 (has links)
Not available / text
|
73 |
Transition metal-mediated cyclizations and synthesis of annonaceous acetogenin analogsGorman, Jeffrey Scott Thomas, 1976- 16 August 2011 (has links)
Not available / text
|
74 |
Oxidative palladium catalysis under aerobic condition: studies on monocyclization of {221}-Keto amides and tandem cyclization ofAlkenyl anilinesYip, Kai-tai., 葉啟泰. January 2005 (has links)
published_or_final_version / abstract / Chemistry / Doctoral / Doctor of Philosophy
|
75 |
Some chemistry of dibenzo-azocine, -azonine and -azecine rings, attempted synthesis of 6, 12-dioxodibenzo[b,f]oxocin, and novelreactions and rearrangements of deoxybenzoin carboxylic acidderivatives郭乃超, Kwok, Nai-chiu. January 1992 (has links)
published_or_final_version / Chemistry / Master / Master of Philosophy
|
76 |
The cycloaddition of electron poor olefins to unsubstituted vinyl aminesGlogowski, Mark Edward, 1943- January 1976 (has links)
No description available.
|
77 |
Carbon-13 nuclear magnetic resonance studies of metal enolates, Part I Part II, The synthesis and cyclization reactions of [omega]-Bromo Ketones Part III, Alkylation studies of the [delta] [superscript 19]-enolate of anti-6-t-butyl-cis and trans-1-decalonePhillips, William Vernon 12 1900 (has links)
No description available.
|
78 |
Model studies toward the total synthesis of jatrophatrione: formation of nine-membered rings via Indian derivativesMcCloskey, Candice Joy 05 1900 (has links)
No description available.
|
79 |
The mechanism of the enzymatic ring expansion of penicillin N to deacetoxycephalosporin CCrouch, Nicholas January 1988 (has links)
The order of events in the Deacetoxycephalosporin C/Deacetylcephalosporrn C Synthetase (DAOC/DAC Synthetase) catalysed ring expansion of penicillin N to deacetoxycephalosporin C has been investigated by the use of labelled/unlabelled penicillin N mixed competitive kinetic isotope effect experiments, in which the labelled penicillin N substrates were either labelled in the pro <strong>R</strong>- and pro <strong>S</strong>-methyl groups or at C-3. In addition, to assisting in the determination of the position of the first irreversible event in this reaction, deuteration at C-3 gave rise to a bifurcation of the natural biosynthetic pathway which led to enhanced production of the shunt metabolite, (2<strong>R</strong>,3<strong>S</strong>,6<strong>R</strong>,7<strong>R</strong>)-l-aza-3- methyl-3-hydroxy-7-[(5<strong>R</strong>)-5-amino-5-carboxy-pentanamido]-8-oxo-5-thiabicyclo[4.2.0]octane-2-carboxylate. The biosynthetic precursor to the 3<strong>S</strong>-hydroxycepham shunt metabolite has been investigated and the origin of the 3<strong>S</strong>-hydroxyl oxygen atom has been determined by the use of labelling studies with <sup>18</sup>O<sub>2</sub> and shown to be derived from molecular oxygen. <sup>13</sup>C-labelling studies are described which indicate that the ring expansion process is stereospecific to within the limits of the detection system employed. These experiments confirm earlier investigations but, in addition to improving upon the assessment of the degree of stereospecificity, have shown that the 3<strong>S</strong>- hydroxycepham shunt metabolite is produced with the same stereospecificity as that observed for the usual biosynthetic products, DAOC and DAC. Chapter 5 describes an investigation of the anomalous C-2 deuterium exchange detected in DAOC produced by incubation of di-(<sup>2</sup>H<sub>3</sub>-methyl)-penicillin N with DAOC/DAC synthetase. The preliminary results from this study indicate that initially exchange occurs stereospecifically with the pro <strong>R</strong> C-2 deuterium atom being replaced by a hydrogen atom. The origins of the unusual tripeptides <strong>L</strong>-α-aminoadipyl-<strong>L</strong>-serinyl-<strong>D</strong>-valine (<strong>L</strong>,<strong>L</strong>,<strong>D</strong>-ASV), α-aminoadipyl-serinyl-isodehydrovaline (ASdV) and α-aminoadipyl-cysteinyl- β-hydroxyvaline (AC-[β-OH]-V) isolated from Penicillium chrysogenum and Cephalosporium acremonium, have been examined by the use of variously <sup>13</sup>C-labelled <strong>L</strong>,<strong>L</strong>,<strong>D</strong>-α-aminoadipyl-cysteinyl-valine (<strong>L</strong>,<strong>L</strong>,<strong>D</strong>-ACV) and <strong>D</strong>,<strong>L</strong>,<strong>D</strong>-α-aminoadipyl- cysteinyl-valine (<strong>D</strong>,<strong>L</strong>,<strong>D</strong>-ACV) tripeptide isotopomers. The initial results obtained from this investigation may be considered as circumstantial evidence that ASdV is formed by the action of IPNS upon <strong>L</strong>,<strong>L</strong>,<strong>D</strong>-ACV. Finally, various substrate analogues have been prepared and evaluated as substrates for the ring expansion and hydroxylation activities of the bifunctional DAOC/DAC synthetase enzyme.
|
80 |
Factors influencing the ring conformations of tris (ethylenediamine) metal complexesHuneke, James T January 1976 (has links)
Typescript. / Thesis (Ph. D.)--University of Hawaii at Manoa, 1976. / Bibliography: leaves 203-208. / Microfiche. / xv, 208 leaves ill
|
Page generated in 0.088 seconds