.
                   on-line      

 SCF-TP on-line  

2018, N3, pp. 77-82

A.A. Philippov, A.M. Chibiryaev

Non-catalytic MeerweinPonndorfVerleyOppenauer Type Reaction of Monoterpenoids in Supercritical Fluids

Catalyst-free MeerweinPonndorfVerleyOppenauer reaction was studied for cyclic monoterpenic ketones and alcohols (menthone, camphor, menthol and borneol) under supercritical conditions. It is shown that ketones can be reducedin supercritical isopropanol with high selectivity (8998 %) under catalyst- and base-free conditions. Conversion of menthone and camphor achieves 63 % (at 350 °C) and 11 % (at 300 °C), correspondingly, for 5 hours. In reversed dehydrogenation of menthol and borneol in sc-acetone, conversion reaches 34 % and 22 %, respectively, while selectivity is 95% and 88 %. In all cases the main side reaction was the thermal dehydrationof alcohols.

Key words: supercriticalfluids, monoterpenic ketones, monoterpenic alcohols, hydrogen transfer reaction

RIS


   © 2006-2007 ""