PROCESSES FOR PREPARING A (1,2-DIMETHYL-3-METHYLENECYCLOPENTYL)ACETATE COMPOUND AND (1,2-DIMETHYL-3-METHYLENECYCLOPENTYL)ACETALDEHYDE
申请人:Shin-Etsu Chemical Co., Ltd.
公开号:EP4101833A1
公开(公告)日:2022-12-14
The present invention provides a process for preparing a (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3), wherein R represents a linear or branched alkyl group having 1 to 4 carbon atoms, the process comprising subjecting a haloacetaldehyde alkyl 2,3-dimethyl-2-cyclopentenyl acetal compound of the following general formula (1), wherein R is as defined above, and Y represents a halogen atom, to a dehydrohalogenation reaction in the presence of a base, followed by a rearrangement reaction to obtain a (1,2-dimethyl-2-cyclopentenyl)acetate compound of the following general formula (2), wherein R is as defined above, and subjecting the (1,2-dimethyl-2-cyclopentenyl)acetate compound (2) to an epoxidation reaction, followed by an isomerization reaction and then a methylenation reaction to obtain the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound of the following general formula (3). The present invention also provides a process for preparing (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde of the following formula (4), the process comprising the aforesaid process for preparing the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3), and converting an alkoxycarbonylmethyl group (i.e., -CH2C(=O)OR) of the (1,2-dimethyl-3-methylenecyclopentyl)acetate compound (3) to a formylmethyl group (i.e., -CH2CHO) to obtain (1,2-dimethyl-3-methylenecyclopentyl)acetaldehyde (4).
本发明提供了一种制备下通式(3)的(1,2-二甲基-3-亚甲基环戊烯基)乙酸酯化合物的工艺,其中R代表具有1至4个碳原子的直链或支链烷基,该工艺包括在碱存在下,使下通式(1)的卤代乙醛烷基2,3-二甲基-2-环戊烯基乙缩醛化合物(其中R如上定义,Y代表卤原子)进行脱氢卤化反应、将(1,2-二甲基-2-环戊烯基)乙酸酯化合物(2)进行环氧化反应,然后进行异构化反应,再进行亚甲基化反应,得到通式(3)的(1,2-二甲基-3-亚甲基环戊基)乙酸酯化合物。本发明还提供了制备下式(4)的(1,2-二甲基-3-亚甲基环戊基)乙醛的工艺,该工艺包括上述制备(1,2-二甲基-3-亚甲基环戊基)乙酸酯化合物(3)的工艺,并将烷氧羰基甲基(即、将(1,2-二甲基-3-亚甲基环戊基)乙酸酯化合物(3)的烷氧羰基甲基(即 -CH2C(=O)OR)转化为甲酰基甲基(即 -CH2CHO),得到(1,2-二甲基-3-亚甲基环戊基)乙醛(4)。