Dsm N.v.

Hubertus J Dielemans

Anna M Castelijns

Richard Green

Alie Kuiterman

The invention relates to a method for preparing an .alpha.-alkylcinnamaldehyde via aldol concensation of a benzaldehyde and an alkanal, with pyrrolidine being employed as a catalyst. The method is suitable, in particular, for preparing .alpha.-hexylcinnamaldehyde by aldol condensation of benzaldehyde and n-octanal, in particular for preparing .alpha.-hexylcinnamaldehyde of olfactory quality, since it was found that, in the method according to the invention, relatively little .alpha.-hexyldecenal, the aldol condensation product of n-octanal, is formed. Preferably, the aldol condensation is carried out without a solvent in the presence of an acid, and the alkanal is metered in over time to a mixture which contains pyrrolidine and benzaldehyde.

Method for preparing an alpha-alkycinnamaldehyde

The invention relates to a method for the preparation of a 2-(2-cyanoethyl)-cyclopentanone by reaction of a cyclopentanone which contains at least one .alpha.-H atom with an .alpha.,.beta.-unsaturated nitrile in the presence of a catalytic amount of pyrrolidine as catalyst and optionally also a catalytic amount of an acid compound. A high selectivity and a high catalyst activity are achieved with the method.

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Beek, Netherlands

Hubertus J Dielemans