Abstract: A process for preparing .alpha.,.alpha.-dialkoxy ketones of the formula I ##STR1## where R.sup.1 and R.sup.2 are each, independently of one another, hydrogen, C.sub.1 -C.sub.20 -alkyl, C.sub.3 -C.sub.20 -cycloalkyl, C.sub.4 -C.sub.30 -cycloalkylakyl, C.sub.9 -C.sub.30 -alkylcycloalkyl, unsubstituted or C.sub.1 -C.sub.8 -alkyl, C.sub.1 -C.sub.8 -alkoxy-, halogen-, C.sub.1 -C.sub.4 -haloalkyl-, C.sub.1 -C.sub.4 -haloalkoxy-, phenyl-, phenoxy-, halophenyl-, halophenoxy- and/or cyano-substituted aryl, C.sub.7 -C.sub.20 -aralkyl or heterocyclyl,R.sup.2 is also ##STR2## R.sup.3 and R.sup.4 are each, independently of one another, C.sub.1 -C.sub.20 -alkyl, C.sub.3 -C.sub.20 -cycloalkyl, aryl, C.sub.7 -C.sub.20 -arylalkyl, or together are an unsubstituted or C.sub.1-C.sub.4 -alkyl- substituted C.sub.2 -C.sub.7 -alkylene chain andR.sup.5 is R.sup.1 or together with R.sup.1 is an unsubstituted or C.sub.1 -C.sub.4 -alkyl-substituted C.sub.2 -C.sub.

Abstract: Novel tert-butylalkynols of the formula (I) ##STR1## where Y is hydrogen, halogen, C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, C.sub.1 -C.sub.4 -haloalkyl, aryl, aryloxy or benzyl and m is an integer from 1 to 3, and the individual groups Y may be identical or different when m>1, and a process for their preparation are described.

Abstract: Phenyl-substituted epoxides of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, alkyl, alkenyl, phenyl, halogen, nitro, alkoxy, haloalkyl, phenoxy or phenylsulfonyl, are prepared by reducing a haloacetophenone to a halohydrin and reacting the halohydrin with an alkali metal hydroxide by a process in which the reduction with the alkali metal borohydride and the reaction are carried out in aqueous organic solution, or the cyclization of a halohydrin with an alkali metal hydroxide is carried out in an organic liquid.

Abstract: Phenylacetaldehydes of the general formula I ##STR1## where R.sup.1 to R.sup.5 are each independently of the others hydrogen, alkyl, alkoxy, halogen, haloalkyl, haloalkoxy or haloalkylthio, by catalytic rearrangement in the presence of a zeolite, are prepared by reacting an epoxy of the formula II or a phenylglycol of the formula III ##STR2## where Y and Z can be identical to or different from each other and are each hydroxyl, alkoxy, aryloxy or acyloxy, in the gas phase over a borosilicate zeolite catalyst at from 70.degree. to 200.degree. C. under reduced pressure.