6-hydroxy-3-pyridazinecarboxylic acid ethyl ester 、
3,4-epoxy-3,4-dihydro-2,2-dimethyl-2H-1-benzopyran-6-carbonitrile 在
吡啶 作用下,
以
乙醇 为溶剂,
反应 2.0h,
以65%的产率得到1-((3S,4R)-6-Cyano-3-hydroxy-2,2-dimethyl-chroman-4-yl)-6-oxo-1,6-dihydro-pyridazine-3-carboxylic acid ethyl ester