Dialkoxyalkenyl alkoxymethyl ether compound and a process for preparing a terminal conjugated alkadienal compound from the same

The present invention provides a process for preparing a terminal conjugated alkadienal compound of the following general formula (5):CH2═CHCH═CH(CH2)aCHO (5)wherein "a" represents an integer of 1 to 15, from a dialkoxyalkenyl alkoxymethyl ether compound of the following general formula (1):R1CH2OCH2OCH2CH2CH═CH(CH2)aCH(OR2)(OR3) (1)wherein R1 represents a hydrogen atom, an n-alkyl group having 1 to 9 carbon atoms, or a phenyl group, R2 and R3 represent, independently of each other, a monovalent hydrocarbon group having 1 to 15 carbon atoms, or R2 and R3 may form together a divalent hydrocarbon group, R2-R3, having 2 to 10 carbon atoms, and "a" is as defined above.