Addition reaction of hydroxy1-containing compounds with alkynes or allenes

A process for the preparation of compounds of the formulae I and II ##STR6## where R.sup.1 is hydrogen or an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radical or an acyl radical, it being possible for these radicals to carry further substituents which do not react with acetylenes or allenes, and the radicals R, independently of one another, are hydrogen or aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radicals which may be bonded to one another with the formation of a ring, and m is 0 or 1, by an addition reaction of a compound of the formula III

• R.sup.1 OH III
• with an acetylene or an allene of the formula IV or V ##STR7## where R.sup.1 and R have the abovementioned meanings, in the gas phase at elevated temperatures in the presence of a heterogeneous catalyst obtained by impregnating silica with an inorganic salt of an element of group 12 of the Periodic Table of Elements, wherein the reaction is carried out at below 200.degree. C. and the catalyst used is one which contains, as an active component, an X-ray amorphous zinc silicate or cadmium silicate containing from 1 to 40% by weight, calculated as oxide, of zinc or cadmium, obtainable by applying a salt of zinc or cadmium and an inorganic oxo acid, which salt is decomposable at below 400.degree. C., to amorphous silica and forming the catalyst before the reaction at from 50 to 500.degree. C. or during the reaction in situ at from 50 to 200.degree. C. in the presence of a hydroxyl-containing compound selected from the group consisting of water, alkanols of 1 to 6 carbon atoms, diols and polyols having 2 to 6 carbon atoms and 2 or 3 OH groups and carboxylic acids of 1 to 6 carbon atoms.