申请人:Shin-Etsu Chemical Co., Ltd.
公开号:EP4101832A1
公开(公告)日:2022-12-14
The present invention provides a process for preparing 2-(1,5,5-trimethyl-2-cyclopentenyl)ethyl acetate of the following formula (3), wherein Ac represents an acetyl group, the process comprising: subjecting a haloacetaldehyde alkyl 3,4,4-trimethyl-2-cyclopentenyl acetal compound of the following general formula (1), wherein R represents a linear or branched alkyl group having 1 to 4 carbon atoms, and Y represents a halogen atom, to a dehydrohalogenation reaction in the presence of a base, followed by a rearrangement reaction to obtain a (1,5,5-trimethyl-2-cyclopentenyl)acetate compound of the following general formula (2), wherein R is as defined above, and subjecting the alkoxycarbonylmethyl group (i.e., -CH2C(=O)OR) of the (1,5,5-trimethyl-2-cyclopentenyl)acetate compound (2) to a multi-step conversion to be converted into a 2-acetoxyethyl group (i.e., -CH2CH2OAc) to obtain 2-(1,5,5-trimethyl-2-cyclopentenyl)ethyl acetate (3).
本发明提供了一种制备下式(3)的 2-(1,5,5-三甲基-2-环戊烯基)乙酸乙酯的工艺,其中 Ac 代表乙酰基,该工艺包括:将下式通式(1)的卤乙醛烷基 3,4,4-三甲基-2-环戊烯基乙缩醛化合物,其中 R 代表具有 1 至 4 个碳原子的直链或支链烷基,Y 代表卤原子、在碱存在下进行脱氢卤化反应,然后进行重排反应,得到下式通式(2)的 (1,5,5-三甲基-2-环戊烯基)乙酸酯化合物,其中 R 如上定义,并使烷氧基羰基甲基(即.e.,-将(1,5,5-三甲基-2-环戊烯基)乙酸酯化合物(2)的烷氧羰基甲基(即 -CH2C(=O)OR)进行多步转化,转化为 2-乙酰氧乙基(即 -CH2CH2OAc),得到 2-(1,5,5-三甲基-2-环戊烯基)乙酸乙酯(3)。