申请人:TAKASAGO INTERNATIONAL CORPORATION
公开号:US20030109755A1
公开(公告)日:2003-06-12
Industrially advantageous processes for producing a 2-alkyl-2-cyclopentenone in high yields starting from a 2-(1-hydroxyalkyl)cyclopentanone or a 2-alkylidenecyclopentanone, which are obtainable from a cyclopentanone and a carbonyl compound. A 2-(1-hydroxyalkyl)cyclopentanone represented by the following general formula (1):
1
(wherein R
1
, R
2
, R
3
, R
4
, R
5
, R
6
and R
7
each independently represents hydrogen atom, an alkyl group having 1 to 10 carbon atoms which may have one or more substituents or an aromatic group which may have one or more substituents, and each of (1) R
6
or R
7
with R
3
and (2) R
6
or R
7
with R
4
or R
5
may be together combined to form a ring which may have a double bond) is subjected to dehydrative isomerization in the presence of a bromine compound and/or an iodine compound.
从环戊酮和羰基化合物中获得的2-(1-羟基烷基)环戊酮或2-烷基亚甲基环戊烯酮,可用于产生高收率的2-烷基-2-环戊烯酮的工业优势过程。其中,2-(1-羟基烷基)环戊酮的通式表示如下(1):1(其中,R1、R2、R3、R4、R5、R6和R7分别独立表示氢原子、1至10个碳原子的烷基,可以具有一个或多个取代基或可以具有一个或多个取代基的芳香基,且(1)R6或R7与R3和(2)R6或R7与R4或R5中的每一个都可以组合在一起形成一个可能具有双键的环)。在溴化物和/或碘化物存在下,对2-(1-羟基烷基)环戊酮进行脱水异构化。