Ketonization of 1,5-Cyclooctadiene by Nitrous Oxide

✍ Scribed by Dmitry P. Ivanov; Konstantin A. Dubkov; Dmitry E. Babushkin; Sergey V. Semikolenov; Gennady I. Panov

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 238 KB
• Volume: 351
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/adsc.200900278

✦ Synopsis

Abstract

The kinetics and mechanism of the liquid phase ketonization of 1,5‐cyclooctadiene (COD) by nitrous oxide have been studied. The reaction proceeds without catalyst in the temperature range 473–553 K with the activation energy 113 kJ mol^−1^ and is first order with respect to the initial reactants. The mechanism includes consecutive ketonization of two CC bonds in the COD molecule, with the intermediate formation of an unsaturated monoketone (MK). Further ketonization of MK leads to two isomeric diketones (DK): 1,4‐ and 1,5‐cyclooctanedione. The 1,5‐DK is a stable final product while the 1,4‐DK undergoes further intramolecular aldol transformation leading to two bicyclic compounds, that retain the same number of carbon atoms. The distribution of mono‐ and diketones in the course of reaction is described by theoretical dependences pointing to identical reactivities of the CC double bonds residing in COD and MK molecules. The ketonization of COD by nitrous oxide exemplifies a prospective way for the preparation of valuable organic products in perfect harmony with the strategy of green chemistry.