Abstract: Higher &agr;,&bgr;-unsaturated alcohols are prepared by monoethynylation of a ketone by the NH3/KOH method, if desired hydrogenation of the acetylene alcohol in the presence of hydrogen over a Pd-containing thin layer catalyst, purifying distillation of the hydrogenation product, preferably in a dividing wall column with recirculation of the unreacted ketone to the ethynylation step, and, if desired, preparation of higher alcohols having in each case 5 more carbon atoms in the chain by reacting the alcohols prepared by monoethynylation and, if desired, partial hydrogenation with alkyl acetoacetates diketene in a Carroll reaction to form ketones and using these as starting materials for the steps ethynylation, optional hydrogenation and fractional distillation.

Abstract: Higher &agr;,&bgr;-unsaturated alcohols are prepared by monoethynylation of a ketone by the NH3/KOH method, if desired hydrogenation of the acetylene alcohol in the presence of hydrogen over a Pd-containing thin layer catalyst, purifying distillation of the hydrogenation product, preferably in a dividing wall column with recirculation of the unreacted ketone to the ethynylation step, and, if desired, preparation of higher alcohols having in each case 5 more carbon atoms in the chain by reacting the alcohols prepared by monoethynylation and, if desired, partial hydrogenation with alkyl acetoacetatesor diketene in a Carroll reaction to form ketones and using these as starting materials for the steps ethynylation, optional hydrogenation and fractional distillation.

Abstract: Alkenes are prepared by partial hydrogenation of alkynes in the liquid phase at from 20 to 250° C. and hydrogen partial pressures of from 0.

Abstract: Process for the continuous preparation of unsaturated ketones of the formula I where the dashed line can be an additional C—C bond, R1 is an alkyl, and R2 is an aliphatic hydrocarbon having from 1 to 37 carbons, a cycloalkyl or a cycloalkylalkyl, by reacting an unsaturated alcohol of the formula II  with an alkyl acetoacetate of the formula III where R3 is an alkyl having from 1 to 5 carbons, in the presence or organic aluminum compounds as catalyst.

Abstract: Alkenes are prepared by partial hydrogenation of alkynes in the liquid phase at from 20 to 250° C. and hydrogen partial pressures of from 0.

Abstract: An improved process for preparing lower unsaturated ketones by reacting the corresponding &agr;,&bgr;-unsaturated alcohols with alkyl acetoacetates in a Carroll reaction in the presence of from 0.1 to 5 mol %, based on the alkyl acetoacetate to be reacted, of an organic aluminum compound as catalyst with elimination and continuous removal by distillation of the alkanol eliminated during the reaction from the alkyl acetoacetate in a reactor system with a fitted fractionation column, wherein A an &agr;,&bgr;-unsaturated alcohol which boils below 140° C. is introduced, in the absence of effective amounts of a solvent, together with the organic aluminum compound into the reaction vessel, B a reaction temperature which is as constant as possible between 170° C. and 250° C.

Abstract: The present invention relates to an improved process for preparing higher unsaturated ketones by reacting the corresponding &agr;,&bgr;-unsaturated alcohols with alkyl acetoacetates in a Carroll reaction , in a reactor system with fitted fractionation column, wherein A the &agr;,&bgr;-unsaturated alcohol is introduced into the reaction vessel together with the organic aluminum compound in the absence of effective amounts of a solvent, and the alkyl acetoacetate is metered into this mixture, B a reaction temperature which is as constant as possible at between 175° C. and 220° C., preferably between 180° C. and 200° C., is adjusted and C during the reaction the content of alkyl acetoacetate in the reaction mixture is adjusted to a value which is as constant as possible at between 1 and 3% by weight.

Abstract: Enol ethers of the formula I where R1 is an aliphatic, cycloaliphatic, araliphatic, aromatic or heterocyclic radical which may 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 to form a ring, and m is 0 or 1, are prepared by reacting an acetal or ketal of the formula II with an acetylene or allene of the formula III or IV where R and R1 have the abovementioned meanings, in the gas phase at elevated temperatures in the presence of a zinc- or cadmium- and silicon- and oxygen-containing heterogeneous catalyst.

Abstract: Unsaturated ketones of the formulae Ia and Ib are prepared by a process consisting of the combination of the following reactions: a) The conventional reaction of an allyl alcohol of the formula IIa or a propargyl alcohol of the formula IIb with an isopropenyl ether of the formula III with formation of a ketal of the formula IV as a byproduct, b) preparation of the isopropenyl ether of the formula III by reacting a ketal of the formula IV with propyne or allene, or a mixture thereof in the gas phase at elevated temperatures in the presence of a heterogeneous catalyst containing zinc or cadmium together with silicon or oxygen, and c) feeding the ketal of the formula IV formed in the reaction (a) into stage (b) for the preparation of the isopropenyl ether of the formula III again.

Abstract: A process for the preparation of acetates of alcohols or phenols, in particular linalyl acetate, by causing alcohols or phenols to react with ketene in the presence of a catalyst, wherein the reaction is carried out using approximately equimolar amounts of linalool and ketene in the presence of a zinc salt of a carboxylic acid, or alternatively in the presence of a zinc compound which forms zinc acetate under the conditions of the reaction, and with vigorous mixing of the reaction mixture.Using this process, linalyl acetate and numerous other acetates interesting as perfumes or active agents can be obtained to a good degree of purity in yields of more than 90% of theory and in very good space-time yields.

Abstract: A process for preparing .gamma.,.delta.-unsaturated ketones of the general formula I ##STR1## by reacting an allyl alcohol of the general formula II ##STR2## in which R.sup.1 is H or a hydrocarbon radical having 1 to 20 carbon atoms, with diketene or an alkyl acetoacetate of the general formula III ##STR3## in which R.sup.2 is alkyl having 1 to 4 carbon atoms in an unmodified or modified Carroll reaction in the presence of an aluminum catalyst, wherein aluminum compounds which are stable liquids at room temperature, or a mixture of such aluminum compounds, which comprise at least one radical formed from an alkyl acetoacetate and 1 or 2 alkoxy radicals, or else comprise exclusively radicals formed from alkyl acetoacetates, which are esterified with sec-butanol or isobutanol, or else are esterified with at least two different alcohols, are used as aluminum catalyst.

Abstract: A process for preparing .gamma.,.delta.-unsaturated ketones bya) reacting vinylcarbinols or propargyl alcohols with alkyl acetoacetates or diketene andb) thermally rearranging the resulting acetoacetates in the presence or absence of an aluminum catalyst to .gamma.,.delta.-unsaturated ketones (Carroll reaction),wherein step a) and/or step b) is carried out in a cyclic carbonate of the formula I or a .gamma.-lactone of the formula II ##STR1## where R.sup.1, R.sup.2 and R.sup.3 are H, or lower alkyl and R.sup.4 is H, lower alkyl, phenyl or methoxymethyl, as solvent.

Abstract: A process for preparing polyenecarbonyl compounds having a high all-E content and their acetals or ketals by aldol condensation or Horner-Emmons reaction comprises carrying out the reaction, for the purposes of the preferred formation of a double bond of E configuration and in order to maintain the E configuration of the double bonds in the stating compounds as completely as possible, in the presence of oxygen or an oxygen-inert gas mixture or nitric oxide or a nitric oxide-inert gas mixture and/or in the presence of specific stable radicals and/or in the presence of quinones or quinone derivatives.