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The attempted conversion, by treatment with CsF/TBFA in MeCN, of acetylated derivatives of 2-chlorodifluoromethyl-2-deoxyhexopyranoses into their corresponding 2-trifluoromethyl derivatives ...was always accompanied by an elimination reaction. Thus, representative educts with the
d-
gluco- and
d-
manno-configuration gave derivatives of 2,3-dideoxy-2-trifluoromethyl-
d-
erythro-hex-2-enopyranose and 1,5-anhydro-2-deoxy-2-trifluoromethyl-
d-
arabino-hex-1-enitol, respectively. X-ray analyses are given for 1,3,4,6-tetra-
O-acetyl-2-chlorodifluoromethyl-2-deoxy-α-
d-mannopyranose and 4,6-di-
O-acetyl-2,3-dideoxy-2-trifluoromethyl-α-
d-
erythro-hex-2-enopyranose.
Alkali metal salts of perfluorinated ‘non-nucleophilic’ complex anions were used for fluoridative degradation of cyclosiloxanes under thermal conditions in the absence and presence of high boiling ...multifunctional etheral solvent. The degradative products consist of fluorosilanes and fluorosiloxanes in low to moderate yields.
The procedure described can simultaneously provide about 3GBq 16α‐18Ffluoroestradiol‐3‐sulphamate and about 1 GBq 16α‐18Ffluoroestradiol‐17β‐sulphamate of high radiochemical purity. By treating ...16α‐18Ffluoroestradiol‐3, 17β‐disulphamate with Kryptofix 2.2.2 and potassium carbonate as a base, 16α‐18Ffluoro‐estradiol‐17β‐sulphamate became accessible with a still higher radioactivity level.
After 16α-18Ffluoroestradiol (18FFES) has been successfully prepared in an automated module, the synthesis of 16α-18Ffluoroestradiol-3,17β-disulphamate (18FFESDS) is described as a module-assisted ...one-pot procedure which can provide 10GBq 18FFESDS with a radiochemical purity better than 99%. The procedure is reliable and reproducible and requires a time of about 90min. Because of its high sulphatase-inhibitory effect 18FFESDS is thought to be a new PET tracer to image sites of high sulphatase activity.
Hexafluoropropene oxide (HFPO) is shown to be a good reagent for the nucleophilic formation of the element–fluorine bond in organoelement compounds. Fluorides of Bi, Sb, Se, Te and I were prepared ...from appropriate oxygen compounds
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