Patent ID: 7339085
Filing Date: 2008-03-04
Classification: C07C

Abstract:
1. A process for preparing 2,7-dimethylocta-2,4,6-trienedial of the formula I, by a) double enol ether condensation of a butenedial bisacetal of the formula II  with an enol ether of the formula III,  in the presence of a Lewis acid catalyst to give a condensation product of the formula IV,  where the radicals R b) hydrolysis of the acetal groups of IV by adding an aqueous acid to form the dialdehyde of the formula V; c) conversion of V into the dialdehyde I by reacting with an aqueous base and d) crystallization of I from the reaction mixture, wherein process steps a) to d) are carried out in the presence of an inert, water-immiscible organic solvent.