Aporphines. 28. Preparation of (-)-N-[3H- and -2H]propylnorapomorphine

Filer, Crist N.; Ahern, David G.; Granchelli, Felix E.; Neumeyer, John L.; Law, Say-Jong

doi:10.1021/jo01305a019

Cited by 15 publications

(12 citation statements)

References 2 publications

(2 reference statements)

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“…Canadian investigators appear to have been the first to publish, 83 the deuteration of alpha-cyclodextrin (cyclohexaamylose) to [2,3,6,6 0 -2 H] alpha-cyclodextrin 8 (above). Using D 2 O at reflux with Raney nickel catalyst, they prepared the compound and characterized it with proton coupled 13 C NMR, clarifying an earlier discrepancy in the literature concerning signal assignments. Curiously, a decade later, Japanese chemists reported 84 essentially the same alpha-cyclodextrin deuteration methodology, but not citing and apparently unaware of the earlier publication just mentioned.…”

Section: Miscellaneous Macrocyclesmentioning

confidence: 73%

“…With a specific activity in excess of 80 Ci/mmol, its 3 H NMR afforded a pattern characteristic of a tritiated propyl side chain 13 and the product was used to further elucidate the tacrolimus binding site.…”

Section: Highly Functionalized Macrocyclesmentioning

confidence: 99%

“…20 To elucidate the mechanism involved, the compound was labelled with 13 C in the 9-position carbonyl group. When subjected to basic conditions it afforded a product consistent with an acyl shift mechanism in accord with expectations.…”

Section: Highly Functionalized Macrocyclesmentioning

confidence: 99%

“…80 The terpene humulene, an isomer of caryophyllene, was labelled in the 2-methyl group with tritium by the preparation and reduction of a bromo precursor with lithium aluminum tritide. 81 With regard to carbon isotopes, the 2-phenylcyclododecanones mentioned earlier were labelled with 13 C via a multi-step path using the ring closure of a bis carboxylic ester. 77 Susan and Duncan successfully prepared [ 14 C 6 ] 1,5,9-cyclododecatriene by the Ziegler catalyst trimerization of [ 14 C] 1,3-butadiene.…”

Section: Miscellaneous Macrocyclesmentioning

confidence: 99%

“…Clearly, some overlap has occurred, and on occasion the placement of certain compounds is somewhat arbitrary. Within each section, the order of discussion typically proceeds through isotopes of increasing atomic weight ( 2 H, 3 H, 13 C, 14 C, etc.) and references are usually arranged from earliest to latest unless the juxtaposition of certain related citations was more appropriate.…”

Section: Introductionmentioning

confidence: 99%

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The preparation of isotopically labelled macrocyclic compounds by organic synthesis

Filer

2001

Labelled Comp Radiopharmac

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Section: Miscellaneous Macrocyclesmentioning

confidence: 73%

Section: Highly Functionalized Macrocyclesmentioning

confidence: 99%

Section: Highly Functionalized Macrocyclesmentioning

confidence: 99%

Section: Miscellaneous Macrocyclesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The preparation of isotopically labelled macrocyclic compounds by organic synthesis

Filer

2001

Labelled Comp Radiopharmac

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Preparation of Tritium‐Labeled Compounds by Chemical Synthesis

2009

Preparation of Compounds Labeled With Tritium and Carbon‐14

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In contrast to isotope exchange methods, which utilize the target compound or a late intermediate as substrate for labeling, chemical synthesis involves transformation of some precursor chemical with concurrent introduction of tritium. Four basic types of transformations are distinguished for discussion each in turn. They are catalytic tritiations (Section 4.1), which usually involve the reduction of a precursor compound using a catalyst and tritium gas; catalytic tritiolyses (Section 4.2), involving the replacement of functional groups by tritium, again using a catalyst and tritium gas; tritide reductions (Section 4.3), utilizing tritiated versions of hydridic reducing reagents; and the use of small tritiated building blocks (Section 4.4) in synthetic operations to construct target molecules.A phenomenon strongly relevant to the catalytic methods discussed in Sections 4.1 and 4.2, and of some relevance also for tritide chemistry (Section 4.3) is solvent exchange. Most catalytic tritiations and tritiolyses are conducted in solution, and a wide variety of solvents have been used, ranging from nonpolar ones to highly polar, hydroxylic media. The properties of the solvent, however, influence not only the course and rate of a heterogeneously catalyzed reaction, but also the extent to which solvent hydrogen may exchange with tritium gas as a side reaction and thereby dilute the isotope introduced into the substrate: solvent exchange. It is commonly recognized that the use of protic solvents for tritiations and tritiolyses increases the risk of obtaining products of less than maximal specific activity, although it is equally clear that such reactions often succeed without dilution of label. The crucial factor in each experiment is the relationship between the rate of the tritium-incorporation reaction and the rate(s) of any tritium-diluting reaction(s). It is documented that the rate of metal-catalyzed exchange between elemental hydrogen and water is significant, especially at low pH 1 , but little quantitative data are available to guide practice. Recently a turnover number of 17.3 h À1 was reported for the exchange between H 2 and 2 H 2 O catalyzed by 10% Pd/C at room temperature and a pressure of 1 atm 2 ; this is rapid enough to provide the basis for an economical method of catalytic deuterium exchange Preparation of Compounds Labeled with Tritium and Carbon-14 Rolf Voges, J. Richard Heys and Thomas Moenius

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