- Synthesis of N-[1-13C]caproyl-N′-phenylthiourea
-
An optimal synthesis of N-[1-13C]caproyl-N′-phenylthiourea with isotopic enrichment 82% is described, starting from barium [ 13C]carbonate, using five synthetic steps. Yields were 95% relative to caproyl chloride and 46% relative to barium carbonate. Oxidation of the title compound with manganese dioxide yields the corresponding ureide. Structural similarities with anticonvulsants such as phenacemide make N-caproyl-N′- phenylthiourea an interesting model compound. Copyright
- Simion, Corina Anca,Postolache, Cristian,Deleanu, Calin,Chirtoc, Ileana,Barna, Catalina Mihaela,Bally, Ioana,Balaban, Alexandra T.
-
-
Read Online
- Potential role of fatty acid initiation in the biosynthesis of the fungal aromatic polyketide aflatoxin B1
-
Earlier work in this laboratory has shown the intact incorporation of [1-13C]hexanoate into averufin (1), a key intermediate in aflatoxin B1 biosynthesis. Parallel experiments with equimolar amounts of [1-13C]butyrate, [1-
- Brobst,Townsend
-
p. 200 - 207
(2007/10/02)
-
- Pseudo One-Step Cleavage of C-C Bonds in the Decomposition of Ionized Carboxyclic Acids. Radical Like Reactions in Mass Spectrometry
-
Metastable molecular ions of hexanoic acid (1) decompose unimolecularly to C2H5. and protonated methacrylic acid (5-H+)(92percent rel. abund.).Investigation of the mechanism reveals that 1) the branched cation radical 11 must be regarded as the essential intermediate in the course of the rearrangement/dissociation reaction and 2) the process commences with intramolecular hydrogen transfer from either C-3 or C-5 to the ionized carbonyl oxygen ("hidden" hydrogen migration).Hydrogen transfer from C-4, which would correspond to the well-known McLafferty rearrangement, is of no importance in the C2H5.-elimination from 1.The same conclusion applies for various alternative mechanisms, as for example a SRi type reaction, 1 -> 2-H+.The gas phase chemistry of the cation radical of 1, and in particular the hydrogen exchange processes between the methylene groups C-2/C-3 and C-5/C-6, is in surprisingly close correspondence to the chemistry of free alkyl radicals. - The syntheses of various 13C and 2H-labelled model compounds are described.
- Weiske, Thomas,Schwarz, Helmut
-
p. 323 - 347
(2007/10/02)
-