- Alkane reaction with a mixture of nitric acid and acetic anhydride
-
Alkanes C6-C10 at 15-20°C react with a mixture of concentrated HNO3 and acetic anhydride to afford nitrates of secondary alcohols in the yield up to 70%. Acetates of secondary alcohols, acetates and nitrates of β-nitroalcohols form in small quantity. Isooctane reacts under milder conditions to give a nitrate of β-nitroalcohol.
- Svetlakov
-
p. 1081 - 1084
(2007/10/03)
-
- Separation of Diastereomeric and Enantiomeric Alkyl Nitrates - Systematic Approach to Chiral Discrimination on Cyclodextrin LIPODEX-D
-
High-resolution gas chromatographic separation of all diastereomeric monomethyl-substituted cyclohexyl nitrates is shown on a nonpolar methylpolysiloxane stationary phase, and the first application of this procedure to the environmental diastereomeric analysis of alkyl nitrates is presented.Two characteristic signals in the achiral analysis of atmospheric samples could be assigned to the smallest alkyl nitrate containing two asymmetric carbon atoms, 3-methyl-2-pentyl nitrate.Retention indices in the temperature-programmed separation based on the n-alkanes were determined.The homologous series of 1-alkyl nitrates were found to be useful as ECD-visible n-alkanes.Enantiomeric separation of alkyl nitrates was achieved on heptakis(3-O-acetyl,-2,6-di-O-pentyl)-β-cyclodextrin (LIPODEX-D).The influence of the nitrooxy group and the alkyl chain length on the chiral discrimination on LIPODEX-D is discussed for 25 chiral alkyl nitrates.The absolute configurations of some alkyl nitrates were assigned by asymmetric synthesis of enantiomerically pure references.The complexity of the alkyl nitrate mixtures present in air samoles does not allow a direct chiral separation as the alkyl nitrates partly coelute on the LIPODEX-D column.Column coupling of LIPODEX-D with a polar achiral stationary phase like polyalkylenglocol (PAG) was successfully applied to solve this problem, and the chiral alkyl nitrates present in a typical air sample were separated.A systematic nomenclature for alkyl nitrates is introduced to handle the steadily growing number of branched and long-chain nitrates detected in environmental analysis. - Keywords: analytical methods; alkyl nitrates; chiral resolution; cyclodextrins; gas chromatography
- Schneider, Manfred,Ballschmiter, Karlheinz
-
p. 539 - 544
(2007/10/03)
-
- Electroorganic chemistry; 145: Coupling reaction of an olefin with a radical NO.3 generated by anodic oxidation of NO-3
-
When NO-3 is electrochemically oxidized in the presence of a variety of terminal and 1,2-disubstituted olefins 1 in a mixed solvent system (MeCN:H2O:Et2O = 10:2:1), a radical NO.3 is generated from NO-3 and nitrate esters 3 are formed by a new coupling reaction of the olefin with the radical. The products 3 can be further transformed into the corresponding alcohols 4 and alkyl iodides 5. Under the same reaction conditions, 1,1-di- and 1,1,2-trisubstituted olefins 6 do not give nitrate esters but afford oxazoline derivatives 7. (1S,5S)-(-)-β-Pinene (13) is diastereoselectively transformed into (1S,2R,5S)-(-)-myrtanol (14) by this technique.
- Shono,Chuankamnerdkarn,Maekawa,Ishifune,Kashimura
-
p. 895 - 897
(2007/10/02)
-
- Alkyl Nitrate Formation from the NOx-Air Photooxidations of C2-C8 n-Alkanes
-
The yields of alkyl nitrates formed in the NOx-air photooxidations of the homologous series of n-alkanes from ethane through n-octane have been determined at 299 +/- 2 K and 735 torr total pressure for two different chemical systems.Alkyl peroxy radicals were generated by reaction of the n-alkanes with OH radicals (generated from the photolysis of methyl nitrite in air) or Cl atoms (from photolysis of Cl2 in air).The alkyl nitrate yields obtained from the two systems, corrected for secondary reactions, were in agreement within the experimental errors and increased monotonically with the carbon number of the n-alkane, from x-air photooxidations of the large n-alkanes.
- Atkinson, Roger,Aschmann, Sara M.,Carter, William P. L.,Winer, Arthur M.,Pitts, James N.
-
p. 4563 - 4569
(2007/10/02)
-