2-Hydroxy-3-methylcyclopent-2-en-1-one was synthesized in a five-step synthesis starting from 2-methyl-1,3-butadiene. Novel intermediate steps include the hot tube isomerization of 1,1-dihalo-2-methyl-2-vinylcyclopropane to give 1-methyl-4,4-dihalocyclopent-1-ene, hydrolysis to 3-methyl-2-cyclopenten-1-one, epoxidation of the latter using a phase transfer catalyst, followed by catalyzed isomerization to produce 2-hydroxy-3-methylcyclopent-2-en-1-one in high overall yield.
2-羟基-3-甲基环戊-2-烯-1-酮是从2-甲基-
1,3-丁二烯开始的五步合成。新颖的中间步骤包括热管异构化1,1-二卤代-2-甲基-2-
乙烯基环丙烷,形成1-甲基-4,4-二卤代环戊-1-烯,
水解成
3-甲基-2-环戊烯-1-酮,使用相转移催化剂对后者进行环氧化,随后催化异构化,产生高总收率的2-羟基-3-甲基环戊-2-烯-1-酮。