Patent ID: 6313354
Filing Date: 2001-11-06
Classification: C07C,C11B

Abstract:
A process for the preparation of aromatic aldehydes having perfume properties wherein the aromatic aldehydes correspond to formula (I): ##STR4##where R.sub.1 is a methyl, ethyl or propyl group, R.sub.2 is a methyl, ethyl, isopropyl, tert.butyl or methoxy group, R.sub.3 is hydrogen or a methoxy group, R.sub.4 is hydrogen or a methyl group, and where the dotted line represents a C--C single bond or a C.dbd.C double bond which can have the E or Z configuration, comprising the steps ofA) reacting a phenone ketal corresponding to formula (II): ##STR5##where X and Y independently of one another represent methoxy, ethoxy, propoxy or butoxy groups and R.sub.1 is a methyl, ethyl or propyl group, R.sub.2 is a methyl, ethyl, isopropyl, tert.butyl or methoxy group, R.sub.3 is hydrogen or a methoxy group and R.sub.4 is hydrogen or a methyl group, with a vinyl ether corresponding to formula (III): ##STR6##where R.sub.5 is an alkyl group containing 1 to 4 carbon atoms, in the presence of a Lewis acid to form an acetal;B) subjecting the acetal to acid hydrolysis to form the corresponding .alpha.,.beta.-unsaturated aldehyde of formula I; and, optionally,C) selectively hydrogenating the C.dbd.C double bond of the aldehyde.