Processes for preparing a 3-isopropenyl-6-heptenal compound and a 6- isopropenyl-3-methyl-3,9-decadienyl carboxylate compound, and an intermediate therefor
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsAkihiro Baba, Takeshi Kinsho, Naoki Ishibashi, Yusuke Nagae
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Abstract
The present invention relates to a process for preparing a 3-isopropenyl-6-heptenal compound of the following formula (2): wherein R1 represents a hydrogen atom or a methyl group, the process comprising: subjecting a 3-isopropenyl-6-heptenoate ester compound of the following formula (1): wherein R1 is as defined above, and R2 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms, to a reduction reaction with a reducing agent to form the 3-isopropenyl-6-heptenal compound (2).
Claims12
A process for preparing a 3-isopropenyl-6-heptenal compound of the following formula (2):
- wherein R1 represents a hydrogen atom or a methyl group,
- the process comprising:
- subjecting a 3-isopropenyl-6-heptenoate ester compound of the following formula (1):
- wherein R1 is as defined above, and R2 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms,
- to a reduction reaction with a reducing agent to form the 3-isopropenyl-6-heptenal compound (2), wherein the reducing agent is selected from a group consisting of a complex hydride, an alkoxy derivative of the complex hydride, and an alkyl derivative of the complex hydride.
A process for preparing a 3-isopropenyl-6-heptenoate ester compound of the following formula (1):
- wherein R1 represents a hydrogen atom or a methyl group, and R2 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms,
- the process comprising:
- subjecting a 4-pentenyltriphenylphosphonium halide compound of the following formula (5):
- wherein R1 is as defined above, Ph represents a phenyl group, and X represents a halogen atom, to a Wittig reaction with a 2-propanone compound of the following formula (6) having a protected hydroxyl group:
- Which R4 represents a protective group for a hydroxyl group,
- to form a 2-methyl-2,6-heptadiene compound of the following formula (7) having a protected hydroxyl group at position 1:
- wherein R1 and R4 are as defined above;
- removing the protective group from the 2-methyl-2,6-heptadiene compound (7) having a protected hydroxyl group at position 1 to form a 2-methyl-2,6-heptadienol compound of the following formula (8):
- wherein R1 is as defined above;
- and
- subjecting the 2-methyl-2,6-heptadienol compound (8) thus obtained to a Johnson-Claisen rearrangement with an orthoacetate ester compound to form the 3-isopropenyl-6-heptenoate ester compound (1).
A 3-isopropenyl-6-methyl-6-heptenoate ester compound of the following general formula (1′):
- wherein R2 represents a monovalent hydrocarbon group having 1 to 10 carbon atoms.
Dependencies are inferred from the claim text.