申请人:Bayer Aktiengesellschaft
公开号:US04992577A1
公开(公告)日:1991-02-12
A process for preparing a compound of the formula ##STR1## in which Y is halogen, alkyl or cycloalkyl optionally substituted by halogen or C.sub.1-4 -alkoxy, alkenyl optionally substituted by halogen, aryl, heteroaryl or alkoxycarbonyl, X is hydrogen, halogen or optionally halogen-substituted alkyl, or X and Y, together with the adjacent C atom, form a saturated cycloalkphatic ring having up to 6 C atoms, and R is hydrogen or C.sub.1 -C.sub.4 -alkyl, comprising reacting an aldehyde of the formula ##STR2## with 2-methylbutan-3-one of the formula ##STR3## in the presence of a hydrohalic acid thereby to form a 4,4-dimethyl-3-halogeno-1-hexen-5-one of the formula ##STR4## in which Hal is halogen, halogenating said compound to produce a compound of the formula ##STR5## and reacting said compound with a base of the formula R--OM (VI) in which M is one equivalent of an alkali or alkaline earth metal ion. Compounds IV and V are new. By suitable conditions the trans isomer is selectively produced.
一种制备公式##STR1##化合物的方法,其中Y是卤素、烷基或环烷基,可选择地被卤素或C.sub.1-4-烷氧基取代,烯基可选择地被卤素取代,芳基、杂环芳基或烷氧羰基,X为氢、卤素或可选择地被卤素取代的烷基,或X和Y与相邻的C原子一起形成具有高达6个C原子的饱和环状烷基环,R为氢或C.sub.1-C.sub.4-烷基,包括在氢卤酸存在下将公式##STR2##的醛与公式##STR3##的2-甲基丁酮反应,从而形成公式##STR4##的4,4-二甲基-3-卤代-1-己烯-5-酮,其中Hal为卤素,卤化该化合物以产生公式##STR5##的化合物,并将该化合物与公式R-OM(VI)的碱反应,其中M为一当量的碱金属或碱土金属离子。化合物IV和V是新的。通过适当的条件,可以选择性地产生反式异构体。