Abstract: α-keto esters are key intermediates for synthesizing cephalotaxine ester alkaloids which exhibit antitumor activity. Therefore, it is very important to study their synthetic methods. This paper reports a modified method for synthesizing a-keto esters. Reaction of Grignard reagent and diethyl oxalate in the absence of water and oxygen under the condition of low temperature and short reaction time afforded the following a-keto esters. Ethyl 5-methyl-2-oxo-caproate(Ⅰ) in 92% yield; Ethyl 6-methyl-2-oxo-heptoate(Ⅱ) in 88% yield; Ethyl 5-ethylene ketal of 2,5-dioxo-caproate(Ⅲ) in 63% yield; Ethyl 6-ethylene ketal of 2,6-dioxo-heptoate(Ⅳ) in 54% yield; Ethyl 2-oxo-octoate (Ⅴ) in 98% yield; Ethyl 4-methyl-2-oxo-valerate (Ⅵ) in 60% yield; and Ethyl 2-oxo-valerate(Ⅶ) in 51% yield. Their structures were proved by their MS and ¹HNMR spectra. Four of them (Ⅰ,Ⅱ,Ⅲ,Ⅳ) have been applied respectively in synthesizing deoxyharringtonine, homo-deoxy harringtonine, harringtonine, and homoharringtonine.