6-Hydroxy-10-methoxy-3-oxo-1,5,6,10b-tetrahydro-oxazolo[4,3-a]isoquinoline-5-carboxylic acid ethyl ester 在
lithium hydroxide 作用下,
以
乙醇 为溶剂,
反应 0.5h,
以105 mg的产率得到6-Hydroxy-10-methoxy-3-oxo-1,5,6,10b-tetrahydro-oxazolo[4,3-a]isoquinoline-5-carboxylic acid