Alpha-halotetramethycyclohexanone, a method for the preparation thereof, and a method for the preparation of a (2,3,4,4-tetramethylcyclopentyl)methy carboxylate compound
AssigneeShin-Etsu Chemical Co., Ltd.
InventorsShinnosuke Wakamori, Naoki Ishibashi, Miyoshi Yamashita, Takeshi Kinsho
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Abstract
A method for the preparation of a sex pheromone of Obscure Mealy bug (OMB), (±)(2,3,4,4-tetramethycyclopentyl) methyl acetate includes a step of subjecting alpha-halotetramethylcyclohexanone to a Favorskii rearrangement to obtain a 2,3,4,4-tetramethylcyclopentane compound (2), a step of subjecting the compound (2) to reduction to obtain (2,3,4,4-tetramethylcyclopentyl)methanol compound (3) and a step of subjection the compound (3) to acylation to obtain a (2,3,4,4-tetramethylcyclopentyl)methyl carboxylate compound (4).
Claims3
A method for the preparation of a (2,3,4,4-tetramethylcyclopentyl)methyl carboxylate compound, comprising
- a step of subjecting alpha-halotetramethylcyclohexanone corresponding to the following general formula (1a) or (1b):
- wherein X is a chlorine atom or a bromine atom,
- to a Favorskii rearrangement to obtain a 2,3,4,4-tetramethylcyclopentane compound corresponding to the following general formula (2):
- wherein R1 is a hydrogen atom or a monovalent C1-15 hydrocarbon group,
- a step of subjecting 2,3,4,4-tetramethylcyclopentane compound (2) to reduction to obtain (2,3,4,4-tetramethylcyclopentyl)methanol corresponding to the following general formula (3):
- and a step of subjecting (2,3,4,4-tetramethylcyclopentyl)methanol (3) to acylation to obtain a (2,3,4,4-tetramethylcyclopentyl)methyl carboxylate compound corresponding to the following general formula (4):
- wherein R2 is a monovalent C1-15 hydrocarbon group.
Alpha-halotetramethylcyclohexanone corresponding to the following general formula (1a) or (1b):
- wherein X is a chlorine atom or a bromine atom.
A method for the preparation of alpha-halotetramethyl-cyclohexanone, comprising
- a step of hydrogenating 3,5,5-trimetyl-4-methylidene-2-cyclohexene-1-one corresponding to the following formula (5):
- to obtain 3,3,4,5-tetramethylcyclohexane-1-one corresponding to the following formula (6):
- and a step of subjecting 3,3,4,5-tetramethylcyclohexane-1-one (6) to halogenation to obtain alpha-halotetramethylcyclohexanone corresponding to said general formula (1a) or (1b).
Dependencies are inferred from the claim text.