bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of glucose‐3 and ‐4‐14C of high specific activity and radiochemical purity
Authors: Sturani E. 
Published: October 2006

AbstractA method for the enzymatic synthesis of hexoses‐3‐14C and hexoses‐4‐14C is presented. The procedure is based on the synthesis of 3‐phosphoglyceric acid‐1‐14C (3PGA) by the action of the ribulose diphosphate carboxylase in the presence of ribulose‐1,5 diphosphate and 14CO2, followed by the reversal of the glycolytic reactions leading from glucose to 3PGA. For the synthesis of hexoses‐3‐14C, dihydroxyacetonephosphate‐1‐14C and cold glyceraldehyde‐3‐P are condensed by the aldolase reaction, while for the synthesis of hexoses‐4‐14C cold dihydroxyacetonephosphate is condensed with glyceraldehyde‐3‐P‐1‐14C. The problems and the results of such syntheses are discussed.
Synthesis and 1H‐NMR spectra of 1,1‐dideutero‐ and 2,2‐dideutero‐4‐phenylbutane
Authors: Sneeden R. P. A. , Zeiss H. H. 
Published: October 2006

AbstractThe specifically deuterated bromides PhCH2CH2CD2CH2Br and PhCH2CH2CH2CD2Br have been prepared in good yields and high isotopic purity. The halides have been used to prepare the corresponding organomagnesium halides and then the solvated triorganochromium compounds. The NMR spectra and C‐D stretching frequencies of the deuterated alkyl halides and of all the intermediates involved in their syntheses are recorded.
Preparation of cholesterol‐25‐3H
Authors: Joly Raymond A. , Sauer Horst H. , Bonner James 
Published: October 2006

AbstractThe synthesis of cholesterol‐25‐3H (9) described here starts with the readily available 3β‐hydroxy‐δ5‐cholenic acid (1). The acetate of this acid was converted to the next higher homolog by the Arndt‐Eistert method. Grignard reaction with methyl iodide gave 25‐hydroxycholesterol (6), which was then brominated. Tritium was finally introduced by treating the 25‐bromocholesterol (8) with LiAl3H4.
Syntheses of l‐β‐cyanoalanine‐4‐14C, l‐asparagine‐4‐14C, and l‐aspartic acid‐4‐14C
Authors: Giza Y.‐H. , Ressler Charlotte 
Published: October 2006

AbstractSyntheses are described from a common labeled intermediate of β‐cyanoalanine, asparagine, and aspartic acid, each of the l configuration and labeled with carbon‐14 in carbon‐four. Radiochemical purities were 96, 99.7, and 99 %. The common source of carbon‐14 was ethyl acetyl‐dl‐β‐cyanoalaninate‐4‐14C, which was prepared from commercially available potassium cyanide‐14C by an extension of the studies of Atkinson and Hellmann and Folz.
Synthesis of 1‐ ethylsulphonylnaphthalene‐4‐(35S)‐sulphonamide, a murine bladder carcinogen
Authors: Turner R. , Dean H. G. 
Published: October 2006

AbstractDiazotisation of 1‐ethylsulphonyl‐4‐naphthylamine followed by treatment with sulphur dioxide‐35S in acetic acid and then cupric chloride gave 1‐ethylsulphonylnaphthalene‐4‐(35S)‐sulphonyl chloride. This gave the title compound by reaction with aqueous ammonia. Total time required was three days.
Tritiation ďhydrocarbures oléfiniques par échange isotopique avec ľhydrogène tritié en présence de gel de silice
Authors: Nicolas Hervé , Paulus Jean‐Marie 
Published: October 2006

AbstractĽéchange isotopique entre ľéthylène, le propylène ou les butènes et ľhydrogène tritié, en présence de gel de silice, s'effectue en deux étapes: tritiation du gel de silice, puis tritiation de ľhydrocarbure. Une étude cinétique de ces deux réactions ďéchange isotopique a été entreprise. Cette méthode de marquage conduit à des activités spécifiques élevées. Les produits de dégradation sont peu abondants lorsque la température reste inférieure à 300 °C.
Darstellung von Cassaidin‐7α‐T und Cassaidinsäre‐7α‐T
Authors: Zelck Ulrich , Malur Johannes , Repke Kurt R. H. 
Published: October 2006

AbstractCassaidin‐7α‐T und Cassaidinsäure‐7α‐ T (spezifische Aktivität jeweils 20 mC/mMol) werden dargestellt durch Reduktion der Ketogruppe an C‐7 von Cassain mit Natriumborhydrid‐T (spezifische Aktivität 80 mC/mMol), gegebenenfalls gefolgt von saurer Hydrolyse des Alkaloids. Die Reduktion der teilweise gehinderten Ketogruppe liefert ausschließlich den äquatorialen Alkohol. Wie gezeigt wird, geht die unerwartete Abwesenheit des axialen Alkohols auf den sterischen Ausschluß seiner Bildung durch die benachbarte cis‐ständige Methylgruppe an C‐14 zurück. Die markierten Verbindungen sind geeignet zur Erforschung des Vorkommens von primären Redoxreaktionen an C‐7 im tierischen Organismus und, wenn dies ausgeschlossen ist, zur Abklärung des allgemeinen Stoffwechsel‐Schicksals der Erythrophleum‐Alkaloide.
The synthesis and purification of 14C‐labeled menthol
Authors: Debardeleben J. F. , Jenkins R. W. , Bailey W. C. , Osdene T. S. 
Published: October 2006

AbstractThe synthesis of 14C‐labeled menthol was accomplished by preparation of 14C‐labeled (±) pulegone. Catalytic hydrogenation and chemical reduction converted (±) pulegone to the isomeric menthols possessing 1.10 mCi total activity. Gas chromatographic separation of this material gave the relative abundance of each isomer.
Preparation of 5‐fluorouracil‐6‐3H of high specific activity
Authors: Filip Jíří , Vyšata František 
Published: October 2006

AbstractIsotopic exchange of hydrogen in a system of solvent‐water‐3H was used to prepare 5‐fluoroorotic acid‐3H(G) which was decarboxylated and the hydrogen‐3H removed from labile bonds to yield 5′‐fluorouracil‐6‐3H. It was found in tracer experiments that a suitable solvent for the isotopic exchange of hydrogen was anhydrous dimethylformamide of dioxane. Water‐3H of high specific activity was prepared in these solvents by reduction of PtO2 to Pt using carrierfree tritium. The specific activity of 5‐fluorouracil‐6‐3H was of the order of Ci/mmole, the radiochemical purity was better than 96 %.
New possibilities of enzymic synthesis of radioactive nucleotides. I. Synthesis of radioactive nucleoside‐5′‐triphosphates by an enzyme of Escherichia coli B
Authors: Nejedlý Zdeněk , Ekl Jindřich , Hybš Karel , Filip Jiří 
Published: October 2006

AbstractPossibilities of enzymic synthesis of nucleoside‐5′‐triphosphates‐14C(U) of adenine, guanine, cytosine and uracil of high specific activity and radiochemical purity by means of a purified enzyme isolated from Escherichia coli B were studied. The effect of enzyme concentration in the reaction mixture in dependence on the time of the enzyme reaction is decisive for an optimal production of radioactive nucleoside‐5′‐triphosphates. A simple and rapid method of preparation of radioactive nucleoside‐5′‐triphosphates, including preparative paper chromatography as the single isolation step, is described and information on the radiolysis of the isolated nucleotides is presented.
Isotopically‐labeled natural products I. Biosynthesis and isolation of 1‐menthol‐14C
Authors: Gager F. L. , Core M. T. , Bass R. T. , Jenkins R. W. 
Published: October 2006

AbstractThe biosynthesis by and the isolation of 1‐menthol‐14C from Mentha arvensis grown in 14CO2 are described. Crystals (18 mg; 3.2 mCi/g) were obtained after column chromatographic purification of the steam distillate of the leaves. Purity of greater than 99.5 % was established by gas‐liquid radiochromatography.
Liquid tritioammonia as a tritiating agent
Authors: Bloss K. 
Published: October 2006

AbstractTritioammonia, 10 Ci/g, tritiated piperidine, 5‐hydroxytryptophan, glutamine, and asparagine by refluxing at −35 °C. Within 1.5 to 6 hours the specific activities reached 0.02, 0.775, 1.24 and 2.48 mCi/mmole, purified. Cyclooctatetraene was not exchangelabeled under these conditions. For liquid‐scintillation counting of tritioammonia, ortho‐bromobenzoic acid in toluene‐dioxan served well. Autoradiolysis was no problem.
The use of [32P] polyphosphoric acid as a Phosphorylating Agent: Syntheses of Phosphorus‐32 Labeled Sugar Phosphates
Authors: Zuleski F. R. , McGuinness E. T. 
Published: October 2006

AbstractPhosphorylation of D‐fructose with [32P]polyphosphoric acid followed by prolonged mild acid hydrolysis at 35 °C gave [32P]D‐fructose 1, 6‐diphosphate. The diphosphate was purified by conversion to the acid‐barium salt. [32P]D‐fructose 6‐phosphate was prepared by two methods : Degradation of the diphosphate by heating with 1N HBr for 1 hour at 88‐90 °C, or, replacing the prolonged mild acid hydrolysis of the phosphorylation mixture in the case of the diphosphate with a one hour treatment at 88‐90 °C. [32P]D‐glucose 6‐phosphate was prepared by dissolving the barium salt of [32P]D‐fructose 6‐phosphate in water and adding a dialyzed solution of phosphoglucose isomerase. The highly insoluble heptahydrate of the barium salt of [32P]D‐glucose 6‐phosphate readily crystallized from solution. Phosphorylation of D‐mannose with [32P]polyphosphoric acid gave [32P]D‐mannose 6‐phosphate, which upon reduction with KBH4, yielded [32P]D‐mannitol 1‐phosphate.
New possibilities of enzyme synthesis of radioactive nucleotides. II. Phosphoribosylation of radioactive bases of nucleic acids by the catalytic effect of unpurified cell‐free extract of Brevibacterium ammoniagenes
Authors: Nejedlý Zdeněk , Škodová Helena , Hybš Karel , Škoda Jan 
Published: October 2006

AbstractThe catalytic properties of an unpurified enzyme preparation from cells of Brevibacterium ammoniagenes toward phosphoribosylation of the individual nucleic acid bases are pronouncedly specific, display a high efficiency toward phosphoribosylation of uracil where the con version to uridine‐5′‐phosphate is quantitative, phosphoribosylation of adenine takes place with lower efficiency and guanine and cytosine are practically not phosphoribosylated at all. Using orotic acid‐14C and a complete inhibition of orotidine 5′‐phosphate decarboxylase by means of 6‐azauridine‐5′‐phosphate, a 60 % production of orotidine‐5′‐phosphate‐14C has been achieved. The catalytic efficiency of the enzyme preparation remains preserved even upon substitution of 5‐phosphoribosyl‐1‐pyrophosphate by its direct metabolic precursors.The possibility of direct application of the unpurified cell‐free extract of the bacteria, the simple composition of the final reaction mixtures and the high degree of production of biologically important compounds makes it possible to employ the method studied for an enzyme synthesis of radioactive uridine‐5′‐phosphate, orotidine‐5′‐phosphate and adenosine‐5′‐phosphate.
The purification of synthetic 14C labelled compounds by the use of preparative paper chromatography
Authors: Falęcki J. 
Published: October 2006

AbstractPreparative paper chromatography (PPC) for the purification of synthetic compounds labelled with 14C : choline, chlormequat, glutamic acid, indoleacetic acid and urea is described. The influence of some parameters as time, amount of substances used and geometry factors (dimensions of paper sheets) on the repeatibility of PPC are given.
Carbon‐14 and tritium labelling ofm‐(1‐methyl‐3‐propyl‐pyrrolidinyl)‐ phenol monohydrochloride (profadol; CI‐572)
Authors: Blackburn C. E. 
Published: October 2006

AbstractCarbon‐14 and tritium labelled preparations of m‐(1‐methyl‐3‐propyl‐3‐pyrrolidinyl)‐phenol monohydrochloride (CI‐572) are described. CI‐572‐14C, with the carbon‐14 label in the C‐2 position of the pyrrolidine moiety, was synthesized in five steps from K14CN. CI‐572‐3H was prepared by heterogeneous platinum‐catalyzed exchange with tritiated water in acetic acid. Characterization of CI‐572‐3H included an evaluation of the tritium label stability in water and in aqueous acidic and basic media.
Synthesis of N‐[4‐(2‐dimethylaminoethoxy) benzyl‐α‐14C]‐3,4,5‐trimethoxybenzamide hydrochloride and N‐[4‐(2‐ methylaminoethoxy)benzyl‐α‐14C]‐3, 4‐diethoxybenzamide hydrochloride
Authors: Wineholt R. L. , Johnson J. D. , Heck P. J. , Kaegi H. H. 
Published: October 2006

AbstractThe anti‐emetic compounds N‐[4‐(2‐dimethylaminoethoxy)benzyl‐α‐14C]‐3,4,5‐trimethoxybenzamide hydrochloride (10) and N‐[4‐(2‐methylaminoethoxy)benzyl‐α‐14C]‐3,4‐diethoxybenzamide hydrochloride (11) were prepared. The synthesis of 10 in four steps provided the purified material in 29 % yield from carbon dioxide. The same series of reactions was used to prepare N‐[4‐(2‐benzylmethylamino‐ethoxy)benzyl‐α‐14C]‐3,4‐diethoxybenzamide (9), which after an additional debenzylation step furnished 11 in 56 % yield based on carbon dioxide.
The preparation of aflatoxins labeled with tritium
Authors: Lijinsky William 
Published: October 2006

AbstractAflatoxins B1 and G1 were labeled with tritium by reaction with tritiated water in the presence of a catalyst. Although considerable decomposition occurred, it was possible to purify the products by thin layer chromatography and crystallization following addition of unlabeled compound. The products were chemically homogeneous and the radiochemical purity was above 82 %. When the exchange was carried out with a natural aflatoxin mixture, the specific activity of the purified G1 was only one‐tenth that of the B1. When the aflatoxin G1 was tritiated alone, the specific activity after dilution was 194 μCi/mg. Similarly, the specific activity of purified tritium labeled aflatoxin B1 was 300 μCi/mg. The problems encountered in labeling with tritium such unstable molecules as the aflatoxins are discussed.
Reactions of salts of deuterated benzenecarboxylic acids
Authors: Ratuský J. 
Published: October 2006

AbstractThe course of transcarboxylation reactions of potassium salts of deuterated benzenecarboxylic acids was investigated. During the reaction rapid random exchange of hydrogen atoms of the benzene ring for deuterium takes place. The probable mechanism of this exchange, which involves the liberation of protons from the benzene ring and the formation of carbanions, is proposed. The mechanism of the deuterium for hydrogen exchange is in agreement with the intermolecular ionic mechanism of the transcarboxylation reaction itself since the formation of carbanions via liberation of protons is a part of this reaction.
A simple procedure for preparation and assay of small quantities of 14C‐labeled long‐chain aliphatic aldehyde
Authors: Calleja G. B. , Rogers Palmer 
Published: October 2006

Abstract(l‐14C)‐dodecanal was synthesized from (l‐14C)‐dodecanoic acid. The two‐step synthesis beginning with 0.9 mg of the acid resulted in an overall yield of 42 % after purification. The final product was separated from the starting material and side products by silicic acid column chromatography. Purity was verified by thin layer chromatography and stimulation of light emission catalysed by bacterial luciferase.
Synthesis of 3‐deuteriocyclopentanone and cyclopentanone‐18O
Authors: Chen T.‐S. , Stephens J. C. , Leitch L. C. 
Published: October 2006

AbstractThe title compounds were prepared by pyrolysis of 3‐deuterioadipic acid and adipic acid‐18O4. The synthesis of the labelled adipic acids is described.
Preparation of ring‐labelled adamantane derivatives. I. 2‐adamantanecarboxylic acid‐2‐14C and 2‐methyladamantane‐2‐14C
Authors: Majerski Z. , Wolf A. P. , Schleyer P. V. R. 
Published: October 2006

AbstractA relatively simple route to 2‐substituted adamantane derivatives labelled with 14C at the 2‐position in the adamantane skeleton was developed. The approach used (Figure I) involved ring expansion of adamantanone by labelled diazomethane, conversion of the resulting 4‐homoadamantanone (II) to diazoketone IV, followed by photolytic Wolff ring contraction to 2‐adamantanecarboxylic acid‐2‐14C (VI). Reduction of the carboxylic acid by conventional procedures gave 2‐methyladamantane‐2‐14C (IX).
Synthèse du chlorhydrate de (+)‐N‐(o‐chlorobenzyl) α‐methyl phénéthylamine marqué en position 7 par 14C (chlorhydrate de clobenzorex)
Authors: Lintermans J. , Benakis A. , Ratouis R. 
Published: October 2006

AbstractNous décrivons la synthése du chlorhydrate de (+)‐N‐(o‐chloro‐benzyl) α‐méthyl phénéthylamine (Chlorhydrate de Clobenzorex) marqué en position 7 par le 14C. Nous avons préparé la (±)‐amphétamine 14C en 5 étapes à partir de l' acide benzoïque 14C‐7. Son dédoublement optique a été eflectué par l'intermédiaire du sel avec l'acide (+)‐tartrique. En modifiant avant la salification la proportion des deux isomères par addition à la (±)‐amphétamine 14C‐7 d'une égale quantité de (+)‐amphétamine non radioactive, nous avons obtenu, après une seule cristallisation, le (+)‐tartrate de (+)‐amphetamine 14C‐7 d'une excellente pureté optique et avec un très bon rendement. Ce sel a conduit à la (+)‐amphétamine 14C‐7 par condensation de la (+)‐amphétamine 14C‐7 avec l'o‐chloro‐appliqué aux eaux‐mères de cristallisation a permis, par addition d'acide (−)‐tartrique, d'isoler la (−)‐amphétamine 14C‐7 d'une activité spécifique de 15 mCi/mM. Nous avons synthétisé le chlorhydrate de (+)‐N‐(o‐chlorobenzyl) α‐méthyl phénéthylamine 14C‐7 par condensation de la (+)‐amphétamine 14C‐7 avec l'o‐chlorobenzaldéhyde, suivie d'une réduction par le borohydrure de sodium. Le produit final a une activité spécifique de 17,2 mCi/mM et une pureté radiochimique de l'ordre de 99 %.
The synthesis of 6‐chloro‐17‐hydroxypregna‐4,6‐diene‐3,20‐dione‐4−14c acetate (chlormadinone‐4−14C acetate)
Authors: Palmer K. H. , Handy R. W. , Wall M. E. 
Published: October 2006

AbstractChlormadinone‐4−14C acetate (V) was synthesized from 17α‐hydroxyprogesterone‐4−14C (I) by dehydrogenation to the 4,6‐diene (II) which was converted to the 6‐chloro‐4,6‐diene (IV) via the intermediate 6α,7α‐epoxy compound (III). Acetylation of (IV) gave chlormadinone‐4−14C acetate in 13% overall yield. A secondary reaction product, 6‐chloro‐androsta‐4,6‐diene‐3,17‐dione‐4−14C was isolated and identified.
Catalytic reduction of 3β‐hydroxyandrost‐4‐ene‐17‐one with tritium. I. The distribution and configuration of label in 3β‐hydroxy‐5α‐androstane‐17‐one (1)
Authors: Abul‐Hajj Yusuf J. 
Published: October 2006

AbstractCatalytic reduction of 3β‐hydroxyandrost‐4‐ene‐17‐one (I) with tritium gas gave a mixture of 3β‐hydroxy‐5α‐androstane‐17‐one (II) and 3β‐hydroxy‐5α‐androstane‐17‐one (III). Oxidation of compound II followed by alkaline equilibration resulted in 37% loss of label from position 4. 5α‐Androstane‐3,7‐dione (IVa) was converted via the 2,4‐dibromide to androst‐4‐ene‐3,7‐dione (VIIIa) with 43% loss of radioactivity from position 5. Chloranil dehydrogenation and alkaline equilibration experiments have shown that the additional label was at C‐6α. The distribution and configuration of label in compound II was found to be 37% 4α, 43% 5α and 20% 6α.
Synthesis of labeled o‐iodohippuric acid
Authors: Wheeler O. H. , Verter H. S. , Feliú L. A. , De Jesús C. R. 
Published: October 2006

AbstractThe reaction of o‐iodohippuric acid with labeled iodide has been shown to afford exclusively labeled o‐iodohippuric acid. The same compound has been synthesized from anthranilic acid. The rate of exchange was sufficiently rapid to permit the preparation of 132I and 128I labeled o‐iodohippuric acid. The mechanism of the exchange is discussed.
Synthesis of 3‐hydroxy‐N,N‐dimethyl‐cis‐crotonamide dimethyl phosphate and its N‐methyl analog labeled with 32P and 14C
Authors: Burton W. B. 
Published: October 2006

AbstractTwo vinyl phosphates, 3‐hydroxy‐N,N‐dimethyl‐cis‐crotonamide dimethyl phosphate, and its N‐monomethyl analog, 3‐hydroxy‐N‐methyl‐cis‐crotonamide dimethyl phosphate, labeled with 32P and 14C in three positions, have been synthesized in milligram amounts. The radiosynthesis routes are reported and the effect of reduced scale preparation is discussed. As the compounds exist in geometric isomers, methods for their separation have been developed. The purity of the cis‐isomers was determined to be 98 to 99%. The yield of 3‐hydroxy‐N,N‐dimethyl‐cis‐crotonamide dimethyl phosphate labeled with 32P was 38%, with 14C‐O‐methyl 73% and with 14C‐N‐methyl 34%. The yield of 3‐hydroxy‐N‐methyl‐cis‐crotonamide dimethyl phosphate labeled with 32P was 38%, with 14C‐O‐methyl 73% and with 14C‐N‐methyl 80%.
The preparation of tritium‐labelled ryanodine
Authors: Fairhurst Alan S. 
Published: October 2006

AbstractA method for preparing tritium‐labelled ryanodine is described. The alkaloid was first brominated, and the bromoryanodines were separated from the reaction mixture by thin layer chromatography; NMR analysis at this stage showed substitution of pyrrole protons by bromine. Bromoryanodine was first hydrogenated, and the product was purified and characterized as ryanodine, to establish the feasibility of the method. Tritium was then reacted with bromoryanodine to yield labelled ryanodine with a specific activity of 2.85 Ci/mmole. No detectable isotope exchange occurred when the labelled alkaloid was incubated in aqueous media at pH 7.0 and 30° C.
The synthesis and purification of pentachloro‐phenol−14C6
Authors: Rogers R. R. , Christia J. E. , Etzel J. E. , Born G. S. 
Published: October 2006

AbstractPentachlorophenol−14C6 was synthesized by chlorinating phenol−14C6 using aluminum chloride as a catalyst. Purification of the labeled pentachlorophenol involved the precipitation of the labeled product from an aqueous alkali solution with hydrochloric acid and two sublimations. Proof of radiochemical purity was determined using thick layer chromatography and autoradiography. Internal liquid scintillation counting techniques were used to determine the specific activity of the compound.
A new synthesis for the preparation of 14C‐labelled alkali cyanides
Authors: Bánfi D. , Mlinkó S. , Palágyi T. 
Published: October 2006

AbstractA convenient gas catalytic process has been developed for the synthesis of radioactive alkali cyanides on micro or semimicro scale. The carbon content of barium carbonate used as starting material can be quantitatively transformed into potassium cyanide in a simple process.
The non‐metabolite residue a limitation to the tracer method
Authors: Rosenblum Charles , Trenner Nelson R. , Wolf Donald E. 
Published: October 2006

AbstractThe occurrence of non‐metabolite residues from labeled drugs administered to animals is discussed. Selected are 14C‐labeled thiabendazole, nitroglycerine, nortriptyline, amitryptiline, p‐dime‐thylaminobenzene, nihydrazone and ronidazole. The rapid degradation which is responsible for the phenomenon requires that all tracer applications in living systems be accompanied by a demonstration of the biological stability of the parent compound.
The purity stabilisation of sodium o‐iodohippurate (131I)
Authors: Lisewska I. , Pasternak A. , Zelenay K. 
Published: October 2006

AbstractTo prevent the autoradiolysis damage in sodium o‐iodohippu‐rate−131 I preparations, various conditions of storage have been tested: storage in isotonic solution frozen at dry ice temperature, and in freeze‐dried state. A preparation which was stable for the guarantee period of about 1 month was obtained by storing it frozen at the temperature about — 70° C. The stability of sodium o‐iodo‐hippurate−131I was compared with that of the similar compound labelled with iodine‐125.
Catalytic reduction of 3β‐hydroxyandrost‐4‐ene‐17‐one with tritium. II. The distribution and configuration of label in 3β‐hydroxy‐5β‐androstane‐17‐one(1)
Authors: Abul‐Hajj Yusuf. J. 
Published: October 2006

AbstractCatalytic reduction of 3β‐hydroxyandrost‐4‐ene‐17one (1) with tritium gas gave a mixture of 3 β‐hydroxy‐5 β‐androstane‐17‐one (II) and 3β‐hydroxy‐5α‐androsiane‐17‐one (III). Oxidation of compound II followed by alkaline equilibration resulted in 29% loss of label. A 29% loss of tritium was observed after bromination of compound II. Dehydrobromination of 4β‐bromo‐5β‐androstane‐3,17‐dione to androst‐4‐ene‐3,17‐dione resulted in 54% loss of tritium. Chloranil dehydrogenation and alkaline equilibration experiments have shown that the remaining radioactivity was at C‐6. Thus the distribution and configuration of label was found to be 29% 4β, 54% 5β, 4.7% 6β and 13% 6α.
Small‐scale degradation of carbon‐14 labelled carboxylic acids. II. Complete degradation of carbon‐14 labelled propionic and n‐butyric acids
Authors: Susan A. B. , Nystrom R. F. 
Published: October 2006

AbstractA chemical degradation and radioassay procedure is described for finding the radioactivity in each carbon‐atom of carbon‐14 labelled propionic and n‐butyric acids. This method has been tested with suitably labelled compounds and found to be isotopically reliable.