1-hydroxy-1-nitrato

Zirconium is the principal FP to arise in oxidation state (IV). Where Zircaloy clad fuel is involved, nonradioactive zirconium isotopes may also be present from fuel can residues. As with ruthenium, there may be a variety of nitrato complexes present in the solution including the aquated complexes Zr(N03)s where x = 1-6, and hydroxy nitrato complexes. However, species containing ZrO " " are not expected to be present since this ion is unstable in aqueous media and is rapidly hydrated to Zr(OH)2. The extraction chemistry is further complicated by the formation of inextractable polymeric species when the Zr" concentration exceeds ca. 10 M. An example of such oligomerization is afforded by the [Zr(0H)2(H20)4]4 ion which contains four Zr ions in a square arrangement linked by two /u-OH ligands on each square edge. Four water molecules complete the Zr coordination sphere in an approximately D2d dodecahedral geometry. 

Piperazin 2,5-Dioxo-l-hydroxy-E16a, 190 (OR-OH) Propansaure 2-Methyl-2-nitrato- -nitril XI/2, 115... 

Carbon-Oxygen Bond Formation. CAN is an efficient reagent for the conversion of epoxides into /3-nitrato alcohols. 1,2-cA-Diols can be prepared from alkenes by reaction with CAN/I2 followed by hydrolysis with KOH. Of particular interest is the high-yield synthesis of various a-hydroxy ketones and a-amino ketones from oxiranes and aziridines, respectively. The reactions are operated under mild conditions with the use of NBS and a catalytic amount of CAN as the reagents (eq 25). In another case, N-(silylmethyl)amides can be converted to A-(methoxymethyl)amides by CAN in methanol (eq 26). This chemistry has found application in the removal of electroauxiliaries from peptide substrates. Other CAN-mediated C-0 bondforming reactions include the oxidative rearrangement of aryl cyclobutanes and oxetanes, the conversion of allylic and tertiary benzylic alcohols into their corresponding ethers, and the alkoxylation of cephem sulfoxides at the position a to the ester moiety. 

Ammonium hexanitratocerate(IV) can be used as a catalyst for the ring opening of epoxides in presence of water, thiols or acetic acid (scheme 21) (Iranpoor et al., 1991). Epoxides react in presence of an excess of nitrate ions and a catalytic amount of ammonium hexanitra-tocerate(IV) in acetonitrile to /3-nitrato alcohols (Iranpoor and Salehi, 1995). A combination of ammonium hexanitratocerate(IV) and A-bromosuccinimide (NBS) transforms epoxides into a-hydroxy ketones (scheme 22) (Surendra et al., 2005). Aziridines give a-aminoketones under the same conditions. 

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