Substd. benzaldehyde di:alkyl acetal prodn. - by electrolysis of corresp. toluene dissolved in alcohol, with hydrogenation of by prod. before recycle

Prodn. of substd. benzaldehyde dialkylacetals (I) comprises electrolytic oxidn. of toluenes (II) (where R1, R2, R3 are H, alkyl, aryl or aralkyl; R1 can also be alkoxy, aryloxy or aralkoxy) in soln. in R4OH (R4 is alkyl) and in presence of a conductivity salt and opt. of base. New feature is that by prods. are sepd., then treated as a soln. in R4OH, with H2 in presence of a hydrogenation catalyst at 0 degrees C to alcohol b.pt., opt. under increased pressure. Soln, is then recycled to oxidn. Soln. of by-prods. may also contain (I) and (II) and H2 used for hydrogenation is pref. taht generated cathodically in the electrolysis stage. (I) are intermediates, by acid hydrolysis, for corresp. benzaldehydes, e.g. anisaldehyde which is a perfume ingredient. (I) are prepd. in high material and current yields and of high purity.