我们前文以1-溴-4-氧-戊烷的乙二醇缩酮制成格氏试剂,再与草酸二乙酯反应,成功地得到相应的α-酮酸酯(Ⅳ)。为推广制备α-酮酸(酯)的一般方法,我们经反复试验,在无水、绝氧、低温及较短的反应时间等条件下,格氏试剂与草酸二乙酯作用,产品经亚硫酸氢钠加成物纯化,得到了收率较高,纯度好的七种α-酮酸酯:5-甲基-2-氧-已酸乙酯(Ⅰ),6-甲基-2-氧庚酸乙酯(Ⅱ),2-氧辛酸乙酯(Ⅴ),4-甲基-2-氧戊酸乙 We have previously described Grignard reagents using 1-bromo-4-oxopentane glycol ketal and subsequent reaction with diethyl oxalate to give the corresponding α-keto esters (IV). To promote the general method for the preparation of α-ketoacid, we have repeatedly tested Grignard reagents and diethyl oxalate under the conditions of anhydrous, anaerobic, low temperature and short reaction time, Purification of sodium bisulfate adduct gave seven α-keto esters with high yield and good purity: ethyl 5-methyl-2-oxo-hexanoate (Ⅰ), 6- Ethyl oxalate (II), ethyl 2-oxooctanoate (V), and 4-methyl-2-oxopentanoic acid ethyl ester