This paper discusses a few specific examples of organ distributions involving positron-emitting nuclides intended to illustrate some specific points in this area. In particular, work with 2-fluoro-2-deoxyglucose will be discussed in some detail, and its distribution in the body compared with the closely related (chemically but not biologically) 3-fluoro-3-deoxyglucose and 1-/sup 11/C-2-deoxyglucose. Other compounds labeled with these two nuclides, and with /sup 13/N and /sup 15/O will also be discussed.

A synthesis of 2-deoxy-D-[1-11C]glucose from H11CN has been developed. This compound is obtained in a radiochemical yield of 30–40% with a synthesis time of 45 min.

Rapid uptake of F-18 FDG was observed in a variety of transplanted and spontaneous tumors in animals. The tumor uptake reached a peak by 30 min and remained relatively constant up to 60 min, with a very slow wash-out of F-18 activity from the tumor thereafter. Tumor-to-normal tissue and tumor-to-blood ratios ranged from 2.10-9.15 and 2.61-17.82, respectively, depending on the type of tumor. A scintiscan of a seminoma in a dog showed very high uptake in the viable part and lack of uptake in the necrotic mass. Toxicological studies in mice using 1000 times human tracer dose (HTD) per wk for 3 wk and in dogs using 50 times HTD per wk for 3 wk did not show any evidence of acute or chronic toxicity.

AbstractThe synthesis of octanal and benzaldehyde, labeled with 11C in the carbonyl position, is reported. Octanal was prepared via an insertion reaction of 11CO into the boroncarbon bond of B‐heptyl‐9‐BBN, followed by oxidative hydrolysis. Benzaldehyde was synthesized by the reaction of phenyl magnesium bromide with 11CO2, and subsequent reduction of the labeled benzoic acid to benzylalcohol which was then oxidized to the final product by CrO2Cl2. Both aldehydes were purified via GLPC, leading to radiochemical purities of > 99.5% in each case. The radiochemical yield for octanal and benzaldehyde was 30 ± 5% and 15 ± 5%, respectively. The overall synthesis time was 50 ± 10 min for each compound.

Hydrogen cyanide (HCN) is a versatile synthon for generating carbon‑carbon and carbon-heteroatom bonds. Unlike other one-carbon synthons (i.e., CO, CO2), HCN can function as a nucleophile (as in potassium cyanide, KCN) and an electrophile (as in cyanogen bromide, (CN)Br). The incorporation of the CN motif into organic molecules generates nitriles, hydantoins and (thio)cyanates, which can be converted to carboxylic acids, aldehydes, amides and amines. Such versatile chemistry is particularly attractive in PET radiochemistry where diverse bioactive small molecules incorporating carbon-11 in different positions need to be produced. The first examples of making [11C]HCN for radiolabeling date back to the 1960s. During the ensuing decades, [11C]cyanide labeling was popular for producing biologically important molecules including 11C-labeled α-amino acids, sugars and neurotransmitters. [11C]cyanation is now reemerging in many PET centers due to its versatility for making novel tracers. Here, we summarize the chemistry of [11C]HCN, review the methods to make [11C]HCN past and present, describe methods for labeling different types of molecules with [11C]HCN, and provide an overview of the reactions available to convert nitriles into other functional groups. Finally, we discuss some of the challenges and opportunities in [11C]HCN labeling such as developing more robust methods to produce [11C]HCN and developing rapid and selective methods to convert nitriles into other functional groups in complex molecules.

A convenient method for the synthesis of 18 F-2-deoxy-2-fluoro-D-glucose (4) and 18 F-2-deoxy-2-fluoro-D-mannose (8) by the direct fluorination of 3,4,6-tri-0-acetyl-D-glucal with 18 F-F 2 is described. 14 C-2-deoxy-2-fluoro-D-glucose has been synthesized from 14 C-3,4,6-tri-0-acetyl-D-glucal (from D-[ 14 c(U)]-glucose) by fluorination with F 2 (Method 1) and CF 3 OF (Method 2). These labeled analogs of 2-deoxy-D-glucose were required for the study of local cerebral glucose metabolism.

18F-2-Deoxy-2-fluoro-D-glucose (18FDG) is rapidly extracted by the mouse heart, and the radioactivity in heart (3-4% per organ) remains relatively constant for 2 hr post injection. The brain uptake (2-3% per organ) remained relatively constant throughout the time course of the study. Liver, lungs, kidneys, small intestine, and blood all showed a rapid clearance of radioactivity after injection of 18FDG. At 120 min the heart-to-lung ratio was 12 and heart-to-liver ratio was 32. Urinary excretion of activity was approximately 16% of the injected dose at 60 min. The uptake of radioactivity by dog heart following the intravenous administration of 18FDG was 2.8-4.1% at 60 min and 2.4% at 135 min; it was regionally distributed, the areas of highest activity being the left ventricle and the interventricular septum. The brain activity was 2.1-3.5% at 120 min, with a ratio of gray matter-to-white matter of 2-3:1. Urinary excretion in dogs was 16% and 50% of the injected dose at 60 and 135 min. The chemical form of the activity in the urine, although unidentified, was not 18F-. Cross-sectional images of the myocardium of the dog after intravenous injection of 18FDG were obtained using emission tomography.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFluorination with molecular fluorine. A convenient synthesis of 2-deoxy-2-fluoro-D-glucoseT. Ido, C. N. Wan, J. S. Fowler, and A. P. WolfCite this: J. Org. Chem. 1977, 42, 13, 2341–2342Publication Date (Print):June 1, 1977Publication History Published online1 May 2002Published inissue 1 June 1977https://doi.org/10.1021/jo00433a037RIGHTS & PERMISSIONSArticle Views582Altmetric-Citations150LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (294 KB) Get e-Alerts Get e-Alerts

AbstractAus dem Tri‐O‐acetylglukal (I) erhält man mit elementarem Fluor unter Verdünnung und bei niederen Temperaturen die beiden Difluor‐Verbindungen (II) und (III).