Verfahren zur Herstellung von Acetalen des 3-Methyl-2-butenals

摘要

The invention relates to a method for producing acetals of formula (I) wherein a) the Rs represent independently from each other a C1-C20 alkyl or C3-C20 alkyl or C3-C20 alkenyl radical or b) both radicals R jointly form units of an optionally C1-C10 alkyl substituted 5-7 membered cyclic acetal, wherein 3-methyl-2-butenal is reacted in the presence of amidosulphonic acid, an N-(C1-C8-alkyl) amidosulphonic acid or an N, N-Di(C1-C8-alkyl)amidosulphonic acid as a catalyst with, in case (a), (a1) an alcohol of general formula (IIa) R-OH wherein R has the meaning cited in (a), a2) an orthoester of general formula (III) HC-(OR)3 wherein R has the meaning cited in (a) or a3) a mixture of an alcohol of general formula (IIa) and an orthoester of general formula (III), and in case (b) with an alcohol of general formula (IIb) wherein m is a number between 2 and 4 and a methylene group in alcohol (IIb) can be substituted by a C1-C10-alkyl group.