（R）-3,3-二甲基-2-羟基-4-氧代丁酸乙酯的不对称合成

摘要

研究了异丁醛与乙醛酸乙酯不对称羟醛缩合反应合成(R)-3,3-二甲基-2-羟基-4-氧代丁酸乙酯,考察了催化剂种类及用量、反应时间、反应溶剂对羟醛缩合反应的影响。确定较佳反应条件为：L-组氨酸作催化剂,用量为乙醛酸乙酯物质的量的30%,乙二醇为溶剂,反应时间24h。( R)-3,3-二甲基-2-羟基-4-氧代丁酸乙酯的收率达75%,ee值为73%。产物结构经1 H NMR,GC-MS进行了表征。%Ethyl(R)-3,3-dimethyl-2-hydroxy-4-oxobutyrate was synthesized by asymmetric aldol reaction using ethyl glyoxylate and isobutyraldehyde as raw material. The effects of aldol reaction conditions,including the type and amount of catalyst,reaction time, reaction solvent,were investigated. The optimal conditions were as follows:L-histidine as catalyst at an amount of 30%of the molar ratio of ethyl glyoxylate. The yield of(R)-3,3-dimethyl-2-hydroxy-4-oxobutyric acid ethyl ester reached 75%in which the enantions-electivity( e. e) of the product gained 73%. The product was characterized by 1 H NMR and GC-MS.