摘要:
2-Methylalk-2-enals of the formula ##STR1## where R.sup.1 and R.sup.2 are each hydrogen, alkyl or an aromatic radical, are prepared by isomerization of an acrolein derivative of the formula ##STR2## with a zeolite catalyst, an aluminum silicate and/or an aluminum phosphate.
摘要:
4-Oxaaldehydes of the formula ##STR1## are prepared by catalytic isomerization of 1,3-dioxanes by a process in which a 1,3-dioxane of the formula ##STR2## where R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are identical or different and are each hydrogen, a straight-chain or branched alkyl, alkenyl or alkynyl radical of not more than 18 carbon atoms, a cycloalkyl or cycloalkenyl radical of 5 to 8 carbon atoms, an aryl, alkylaryl, aralkyl or alkenylaryl radical of 5 to 16 carbon atoms or a heterocyclic radical, and furthermore R.sup.1 and R.sup.2 and/or R.sup.4 and R.sup.5 together with the carbon atom to which they are bonded may form a cycloalkane, a cycloalkene or a heterocyclic structure, and the stated radicals may furthermore carry substituents which are inert under the reaction conditions, and R.sup.3 is hydrogen or straight-chain or branched alkyl, is isomerized using a phosphate as a catalyst.
摘要:
Cyclic 6-membered to 8-membered 1,2-vinylenedioxy compounds of the general formula I ##STR1## where A is ##STR2## R.sup.1 to R.sup.7 independently of one another are each hydrogen, C.sub.1 -C.sub.8 -alkyl, C.sub.2 -C.sub.16 -alkoxyalkyl, C.sub.2 -C.sub.8 -alkenyl, C.sub.2 -C.sub.8 -alkynyl, C.sub.5 -C.sub.8 -cycloalkyl, aryl, C.sub.7 -C.sub.10 -alkylphenyl, C.sub.7 -C.sub.10 -phenalkyl, C.sub.8 -C.sub.10 -phenalkenyl or a heterocyclic structure, or R.sup.2 and R.sup.3, R.sup.2 and R.sup.4, R.sup.3 and R.sup.4, R.sup.2 and R.sup.6, R.sup.3 and R.sup.6, R.sup.4 and R.sup.5 or R.sup.6 and R.sup.7 together form a cycloaliphatic or heterocyclic ring, and R.sup.1 to R.sup.7 may furthermore carry substituents which are inert under the reaction conditions, and n is 0 or 1, are prepared by a process in which a cyclic 2-oxymethyl-1,3-dioxa compound or one of its derivatives of the general formula II ##STR3## where R.sup.1 to R.sup.7, A and n have the abovementioned meanings, and R.sup.8 is hydrogen or C.sub.1 -C.sub.12 -alkyl, is converted in the presence of an acidic catalyst at from 150.degree. to 450.degree. C. and under from 0.001 to 50 bar, some of the compounds obtained being novel.
摘要:
4-oxaaldehydes of the formula ##STR1## are prepared by catalytic isomerization of 1,3-dioxanes by a process in which a 1,3-dioxane of the formula ##STR2## where R.sup.1, R.sup.2, R.sup.4 and R.sup.5 are identical or different and are each hydrogen, a straight-chain or branched alkyl, alkenyl or alkynyl radical of not more than 18 carbon atoms, a cycloalkyl or cycloalkenyl radical of 5 to 8 carbon atoms, an aryl, alkylaryl, aralkyl, aralkenyl or alkenylaryl radical of 5 to 16 carbon atoms or a heterocyclic radical and furthermore R.sup.1 and R.sup.2 and/or R.sup.4 and R.sup.5 together with the carbon atoms to which they are bonded may form a cycloalkane, a cycloalkene or a heterocyclic structure, and the stated radicals may furthermore carry substituents which are inert under the reaction conditions, and R.sup.3 is hydrogen or straight-chain or branched alkyl, is isomerized using a metal oxide catalyst, which has been treated with an acid, and/or a silica phase having a zeolite structure.
摘要:
Olefinically unsaturated carboxylic esters having a terminal ester group and of the general formulae Ia and IbR.sup.1 --CH.sub.2 --CH.dbd.CH--(CH.sub.2).sub.r--1 --COOR.sup.2 (Ia)R.sup.1 --CH.dbd.CH--(CH.sub.2).sub.r --COOR.sup.2 (Ib)and, if desired, further double bond isomers, where R.sup.1 is hydrogen or an organic radical, R.sup.2 is C.sub.1 -C.sub.8 -alkyl and r is from 1 to 20, are prepared by a process in which an .alpha.-substituted .alpha.,.omega.-(n-alkylenedicarboxylic ester) of the general formula II ##STR1## where R.sup.1 and R.sup.2 and r have the abovementioned meanings and R.sup.3 is C.sub.1 -C.sub.8 -alkyl, is converted over an acidic heterogeneous catalyst at from 150.degree. to 800.degree. C. and under from 0.01 to 50 bar.
摘要:
Pentenoic esters are prepared by heating formylvaleric esters at from 50.degree. to 400.degree. C. in the presence of zeolites or one or more phosphates selected from the group consisting of aluminum phosphate, silicon aluminum phosphate, boron aluminum phosphate, silicon iron aluminum phosphate, cerium phosphate, zirconium phosphate, boron phosphate, iron phosphate and strontium phosphate.
摘要:
Dienes are prepared by dehydration of aldehydes at elevated temperatures by a method in which the dehydration is carried out using a zeolite as a catalyst.
摘要:
Caprolactam is prepared by heating a 6-aminocaproic ester in liquid phase in the presence of water to 230.degree.-350.degree. C. under superatmospheric pressure in a reaction medium comprising a liquid aromatic hydrocarbon having a boiling point of from 80.degree. to 240.degree. C. which is inert under reaction conditions, and isolating caprolactam from the reaction mixture.