Using the cis -fused cyclopentane-1,4-lactone, (1 R ,5 S ,7 R ,8 R )-7,8-dihydroxy-2-oxabicyclo[3.3.0]oct-3-one ( 1 ), as starting material, 5-deoxycarba-β -L -xylo -hexofuranose ( 6 ) together with α -( 12 ) and β -1-amino-1,5-dideoxycarba-L -xylo -hexofuranose ( 16 ) have been prepared using a number of stereoselective transformations. The key step was the regioselective opening of the epoxide (1 R ,5 S ,7 R ,8 R )-7,8-epoxy-2-oxabicyclo-[3.3.0]oct-3-one ( 4 ) with different nucleophiles.
SummaryCurrently, Ragaglitazar is being developed as a drug for the treatment of hyperglycaemia and hyperlipidemia in patients with type 2 diabetes. Here, we report the labelling of Ragaglitazar with carbon-14 and tritium for in vivo and in vitro investigations. Two different carbon-14 labelled as well as two different tritium labelled tracers of Ragaglitazar were synthesised. The carbon-14 label was introduced from either ethyl bromo[2-14 C]acetate (5 steps/33% overall yield) or [U-14 C]phenoxazine (4 steps/48% overall yield). Tritium was incorporated either by catalytic tritiation of an alkene precursor followed by chiral HPLC separation (2 steps/17% overall yield) or by catalytic tritiumhalogen exchange of an aryl bromide precursor (2 steps/68% overall yield).
SummaryFast and efficient tritium labelling of the nonsteroidal anti-inflammatory drugs naproxen, tolmetin and zomepirac is reported. Naproxen along with its (R)-enantiomer were labelled by catalytic tritium-halogen exchange of the corresponding 5-bromo derivatives providing
SummaryThe potent quorum sensing inhibitor (5Z)-4-bromo-5-(bromomethylene)-2(5H)- C]acetate with ethyl acetoacetate followed by decarboxylation was accelerated by microwave heating to afford [1-14 C]levulinic acid. Subsequently, bromination and oxidation gave the targeted furan-2-one with a radiochemical purity of >97% and a specific activity of 57 mCi/mmol.
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