Provided are a method for producing 3-methylglutaraldehyde in a good yield under a mild condition and a novel acetal compound which is useful for carrying out the foregoing method. The method is a production method of 3-methylglutaraldehyde including a step of hydrolyzing a compound represented by the following general formula (1): ##STR00001##
wherein R.sup.1 and R.sup.2 each independently represent an alkyl group having 1 to 6 carbon atoms, or are mutually coupled to represent an alkylene group having 2 to 6 carbon atoms.

Provided are a method for producing 3-methylglutaraldehyde in a good yield under a mild condition and a novel acetal compound which is useful for carrying out the foregoing method. The method is a production method of 3-methylglutaraldehyde including a step of hydrolyzing a compound represented by the following general formula (1): ##STR00001##
wherein R.sup.1 and R.sup.2 each independently represent an alkyl group having 1 to 6 carbon atoms, or are mutually coupled to represent an alkylene group having 2 to 6 carbon atoms.

Provided are a method for producing a terminal conjugated dienal compound without an oxidation reaction and a terminal hydroxyacetal compound useful as an intermediate in the method. More specifically, provided are a method for producing an (E)-dienal compound comprising the steps of: a metalation reaction of an alkynal acetal compound (1) to obtain an organic metal compound (2), an addition reaction of (2) to ethylene oxide to obtain a hydroxyalkynal acetal compound (3), a reduction reaction of (3) to obtain an (E)-hydroxyalkenal acetal compound (4), a functional group conversion reaction of (4) to obtain an (E)-alkenal acetal compound (5) having a leaving group X, an elimination reaction of (5) to obtain an (E)-dienal acetal compound (6), and a hydrolysis reaction of (6) to obtain the (E)-dienal compound (7); and others. ##STR00001##

Provided are a method for producing a terminal conjugated dienal compound without an oxidation reaction and a terminal hydroxyacetal compound useful as an intermediate in the method. More specifically, provided are a method for producing an (E)-dienal compound comprising the steps of: a metalation reaction of an alkynal acetal compound (1) to obtain an organic metal compound (2), an addition reaction of (2) to ethylene oxide to obtain a hydroxyalkynal acetal compound (3), a reduction reaction of (3) to obtain an (E)-hydroxyalkenal acetal compound (4), a functional group conversion reaction of (4) to obtain an (E)-alkenal acetal compound (5) having a leaving group X, an elimination reaction of (5) to obtain an (E)-dienal acetal compound (6), and a hydrolysis reaction of (6) to obtain the (E)-dienal compound (7); and others. ##STR00001##

Provided are a method for producing a terminal conjugated dienal compound without an oxidation reaction and a terminal hydroxyacetal compound useful as an intermediate in the method. More specifically, provided are a method for producing an (E)-dienal compound comprising the steps of: a metalation reaction of an alkynal acetal compound (1) to obtain an organic metal compound (2), an addition reaction of (2) to ethylene oxide to obtain a hydroxyalkynal acetal compound (3), a reduction reaction of (3) to obtain an (E)-hydroxyalkenal acetal compound (4), a functional group conversion reaction of (4) to obtain an (E)-alkenal acetal compound (5) having a leaving group X, an elimination reaction of (5) to obtain an (E)-dienal acetal compound (6), and a hydrolysis reaction of (6) to obtain the (E)-dienal compound (7); and others. ##STR00001##

The present invention provides a process for preparing an 11-halo-3-undecene compound (7) in which X.sup.1 represents a halogen atom, the process comprising a step of subjecting a nucleophilic reagent, 3-hexenyl compound (5): in which M.sup.2 represents Li or MgZ.sup.2, wherein Z.sup.2 represents a halogen atom or a 3-hexenyl group, to a coupling reaction with a 1-halo-5-halopentane compound (6) in which X.sup.3 and X.sup.4 may be same with or different from each other and represent a halogen atom, to produce the 11-halo-3-undecene compound (7). The present invention also provides a process for preparing a 9-dodecenal compound (4): the process comprising a step of subjecting a nucleophilic reagent, 8-undecenyl compound (1) in which M.sup.1 represents Li or MgZ.sup.1, wherein Z.sup.1 represents a halogen atom or an 8-undecenyl group, and an orthoformic ester compound (2) in which R may be same with or different from each other and represents an alkyl group having 1 to 6 carbon atoms, to a nucleophilic substitution reaction to produce a 1,1-dialkoxy-9-dodecene compound (3) in which R are as defined above; and hydrolyzing the 1,1-dialkoxy-9-dodecene compound (3) thus obtained to produce the 9-dodecenal compound (4). ##STR00001##

The present invention provides a process for preparing an 11-halo-3-undecene compound (7) in which X.sup.1 represents a halogen atom, the process comprising a step of subjecting a nucleophilic reagent, 3-hexenyl compound (5): in which M.sup.2 represents Li or MgZ.sup.2, wherein Z.sup.2 represents a halogen atom or a 3-hexenyl group, to a coupling reaction with a 1-halo-5-halopentane compound (6) in which X.sup.3 and X.sup.4 may be same with or different from each other and represent a halogen atom, to produce the 11-halo-3-undecene compound (7). The present invention also provides a process for preparing a 9-dodecenal compound (4): the process comprising a step of subjecting a nucleophilic reagent, 8-undecenyl compound (1) in which M.sup.1 represents Li or MgZ.sup.1, wherein Z.sup.1 represents a halogen atom or an 8-undecenyl group, and an orthoformic ester compound (2) in which R may be same with or different from each other and represents an alkyl group having 1 to 6 carbon atoms, to a nucleophilic substitution reaction to produce a 1,1-dialkoxy-9-dodecene compound (3) in which R are as defined above; and hydrolyzing the 1,1-dialkoxy-9-dodecene compound (3) thus obtained to produce the 9-dodecenal compound (4). ##STR00001##

The present invention provides a process for preparing an 11-halo-3-undecene compound (7) in which X.sup.1 represents a halogen atom, the process comprising a step of subjecting a nucleophilic reagent, 3-hexenyl compound (5): in which M.sup.2 represents Li or MgZ.sup.2, wherein Z.sup.2 represents a halogen atom or a 3-hexenyl group, to a coupling reaction with a 1-halo-5-halopentane compound (6) in which X.sup.3 and X.sup.4 may be same with or different from each other and represent a halogen atom, to produce the 11-halo-3-undecene compound (7). The present invention also provides a process for preparing a 9-dodecenal compound (4): the process comprising a step of subjecting a nucleophilic reagent, 8-undecenyl compound (1) in which M.sup.1 represents Li or MgZ.sup.1, wherein Z.sup.1 represents a halogen atom or an 8-undecenyl group, and an orthoformic ester compound (2) in which R may be same with or different from each other and represents an alkyl group having 1 to 6 carbon atoms, to a nucleophilic substitution reaction to produce a 1,1-dialkoxy-9-dodecene compound (3) in which R are as defined above; and hydrolyzing the 1,1-dialkoxy-9-dodecene compound (3) thus obtained to produce the 9-dodecenal compound (4). ##STR00001##

The present invention refers to a process for producing 5-[4-(2-hydroxy-2-methyl)-1-oxo-prop-1-yl]-3-[4-(2-hydroxy-2-methyl)-1-oxo-prop-1-yl-phenyl]-2,3-dihydro-1,1,3-trimethyl-1H-indene (dimer isomer 5) that comprises the synthesis from cumene and dimerization of 2-methyl-1-(4-(prop-1-en-2-yl)phenyl)propan-1-one in the presence of acid catalysts.

The present invention refers to a process for producing 5-[4-(2-hydroxy-2-methyl)-1-oxo-prop-1-yl]-3-[4-(2-hydroxy-2-methyl)-1-oxo-prop-1-yl-phenyl]-2,3-dihydro-1,1,3-trimethyl-1H-indene (dimer isomer 5) that comprises the synthesis from cumene and dimerization of 2-methyl-1-(4-(prop-1-en-2-yl)phenyl)propan-1-one in the presence of acid catalysts.