| US 7,339,085 B2 | ||
| Method for producing 2,7-dimethyl-octa-2,4,6-trienedial | ||
| Hansgeorg Ernst, Speyer (Germany); Klaus Henrich, Haβloch (Germany); and Andreas Keller, Speyer (Germany) | ||
| Assigned to BASF Aktiengesellschaft, (Germany) | ||
| Appl. No. 10/588,683 PCT Filed Feb. 04, 2005, PCT No. PCT/EP2005/001138 § 371(c)(1), (2), (4) Date Aug. 08, 2006, PCT Pub. No. WO2005/077874, PCT Pub. Date Aug. 25, 2005. |
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| Claims priority of application No. 10 2004 006 579 (DE), filed on Feb. 10, 2004. | ||
| Prior Publication US 2007/0244344 A1, Oct. 18, 2007 | ||
| Int. Cl. C07C 45/45 (2006.01) | ||
| U.S. Cl. 568—486 [568/494] | 11 Claims |
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 R1 and R2 in formulae II to IV are independently of one another C1-C6-alkyl;
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.
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