Abstract: The present invention relates to [1] a process for producing a 2-alkyl-2-cycloalken-1-one represented by the following general formula (2), which includes the step of subjecting a 2-(1-hydroxyalkyl)cycloalkan-1-one to dehydration and isomerization in the co-existence of an acid and a platinum group metal catalyst, and [2] a process for producing an alkyl(3-oxo-alkylcycloalkyl)acetate which is useful as a perfume material, using the 2-alkyl-2-cycloalken-1-one: wherein n is an integer of 1 or 2; and R1 and R2 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms with the proviso that R1 and R2 may form a ring through a carbon atom adjacent thereto.

Abstract: The present invention relates to a process for producing a 2-alkyl-2-cycloalken-1-one represented by the following general formula (2), including the step of reacting a 2-alkylidene cycloalkanone in the presence of a palladium and/or platinum catalyst which is treated in the following steps (a) and (b); and a method for activating the palladium and/or platinum catalyst including the following steps (a) and (b): Step (a): activating the palladium and/or platinum catalyst in an atmosphere containing a hydrogen gas; and Step (b): replacing the hydrogen gas being present as the atmosphere for the catalyst in the step (a), with an inert gas to remove the hydrogen gas out of the reaction system, wherein m is 0 to 3; n is 1 or 2; R1 and R2 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; and R3 is an alkyl group having 1 to 5 carbon atoms. In accordance with the present invention, the 2-alkyl-2-cycloalken-1-one can be produced with a high purity and a high productivity.

Abstract: The present invention relates to a process for producing a 2-alkyl-2-cycloalken-1-one represented by the following general formula (2), including the step of reacting a 2-alkylidene cycloalkanone in the presence of a palladium and/or platinum catalyst which is treated in the following steps (a) and (b); and a method for activating the palladium and/or platinum catalyst including the following steps (a) and (b): Step (a): activating the palladium and/or platinum catalyst in an atmosphere containing a hydrogen gas; and Step (b): replacing the hydrogen gas being present as the atmosphere for the catalyst in the step (a), with an inert gas to remove the hydrogen gas out of the reaction system, wherein m is 0 to 3; n is 1 or 2; R1 and R2 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms; and R3 is an alkyl group having 1 to 5 carbon atoms. In accordance with the present invention, the 2-alkyl-2-cycloalken-1-one can be produced with a high purity and a high productivity.

Abstract: The present invention relates to [1] a process for producing a 2-alkyl-2-cycloalken-1-one represented by the following general formula (2), which includes the step of subjecting a 2-(1-hydroxyalkyl)cycloalkan-1-one to dehydration and isomerization in the co-existence of an acid and a platinum group metal catalyst, and [2] a process for producing an alkyl(3-oxo-alkylcycloalkyl)acetate which is useful as a perfume material, using the 2-alkyl-2-cycloalken-1-one: wherein n is an integer of 1 or 2; and R1 and R2 are each independently a hydrogen atom or an alkyl group having 1 to 8 carbon atoms with the proviso that R1 and R2 may form a ring through a carbon atom adjacent thereto.

Abstract: The present invention provides a process for producing a muscone represented by (1) by subjecting a citronellic acid derivative and an undecenoate to a Claisen condensation reaction to produce a keto ester compound represented by (2) decarboxylating the keto ester compound to produce 2,6-dimethyl-8-oxy-2,17-heptadecadiene, cyclizing the heptadecadiene using a metathesis catalyst to produce a 6-dehydromuscone represented by (3) and then hydrogenating the double bond.

Abstract: The present invention provides a process for producing a muscone represented by (1) by subjecting a citronellic acid derivative and an undecenoate to a Claisen condensation reaction to produce a keto ester compound represented by (2) decarboxylating the keto ester compound to produce 2,6-dimethyl-8-oxy-2,17-heptadecadiene, cyclizing the heptadecadiene using a metathesis catalyst to produce a 6-dehydromuscone represented by (3) and then hydrogenating the double bond. The present invention also provides the keto ester compound.