摘要:

AbstractHydroxybenzaldehyde, die in der Carbonylgruppe mit14C markiert sind, lassen sich einfach in einer dreistufigen Reaktionsfolge darstellen. Cu14CN — erhalten aus K14CN — und Bromphenole geben Hydroxyarylnitrile‐(nitril‐14C), die mit Raney‐Nickel und Natrium‐hypophosphit zu den entsprechenden Hydroxybenzaldehyden‐(carbonyl‐14C) reduzier

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050102

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractOestrone‐4‐14C in dimethyl sulphoxide solution has been treated with lithium acetylide (ethylene diamine complex) to give ethynyloestradiol‐

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050103

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractHydrogen‐tritium exchange labelling methods proved to be unsatisfactory for the preparation of tritiated DL‐α‐tocopherol at high specific activity. The preparation of α‐tocopherol specifically labelled in the 5‐methyl hydrogen positions is described : the method permits specific activities in the curies per millimole range to be readily achieved. The synthesis is also suitable for preparing tocopherol doubly labelled with tritium and carbon‐14. The stability of the tritiated vitamin on storage

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050104

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractSynthetic oestrogens of the trans‐stilbene and sym. diphenyl‐ethane series have been labelled by catalytic exchange with isotopic water in the presence of heterogeneous platinum. Experiment showed that platinum oxide pre‐reduced with sodium borohydride produced a more suitable catalyst for the exchange than the alternative of self‐activation. Self‐activated catalysts accentuated degradation of the substrate. The labelling method was suitable for the tritiation of all ten substances studied and also for their deuteration with the exception of 4,4′‐dimethoxy‐α‐chloro‐α‐methyl stilbene. Methoxy groups on the aromatic rings sterically hinder exchange in adjacent positions. Steric hindrance to labelling of hydrogens on the bridge carbon atoms was also noted. The results are shown to be consistent with a π‐co

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050105

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractDL‐tyrosine‐4‐14C has been synthesized with an overall yield 29.3 % based on phenol‐1‐14C as the starting material. Anisole‐I‐14C was prepared by methylation of phenol‐1‐14C with dimethyl sulfate. The radioactive anisole was then converted to p‐anisaldehyde‐4‐14C by a modified Gattermann reaction and then condensed with hydantoin to give 5‐(4‐methoxybenzylidene‐4‐14C) hydantoin. The hydantoin was then c

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050106

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractA quick and convenient procedure for the degradation of sugars has been worked out. The quantitative conversion of glucose to lactic acid by the use of commercially available enzymes, followed by the chemical degradation of the latter compound, allows to discriminate between the carbons 1 and 6, 2 and 5, 3 and 4 of the molecule. Moreover the enzymatic conversion of glucose to glycerol‐1‐phosphate and to 3‐phosphoglyceric acid allows to separate the glucose molecule into the two moieties, that is to discriminate between carbons 1, 2, 3 and 4, 5, 6.The problems and the results of this degradation procedure are disc

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050107

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

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 and14CO2, 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

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050108

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

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 recorde

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050109

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractEstrone,6‐7‐3H in benzene has been found to exhibit greater decomposition when stored at −5 °C than when stored at +5 °C. The reason is attributed to lack of uniform dispersal of the solute due to solvent crystallization. The non‐distillable residues from commercial solvents have been found to cause rapid destruction of a stored radiochemical if not removed before storage. Data is presented which indicates that the best method for reducing the total amount of decomposition of labeled steroids which are stored for extended periods of time is repurification at regular time

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050110

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY

摘要:

AbstractLe parapolyphényle (C6H4)nprésente une grande stabilité thermique et moléculaire (anneau benzénique) alliée à une haute teneur en hydrogène. Ces caractéristiques nous autorisent à tenter la tritiation de ce polymère à très haute activité spécifique. Ainsi trilié, ce dernier est susceptible ďětre utilisé comme cible pour la production de neutrons de 14 MeV dans les petits accélérateurs. Ľétude de la microsynthèse du polyphényle tritié fait ľobjet de ce travail.Deux microsynthèses ont été effectuées conduisant à des activités spécifiques de 17 C/mM et 31 C/mM. Les rendements isotopiques de synthèse et ľautoradiolyse de ce

ISSN:0022-2135    

DOI:10.1002/jlcr.2590050111

出版商:John Wiley&Sons, Ltd.    

年代:1969

数据来源: WILEY