6-cyano-2,2-dimethylchromene-3,4-epoxide 、
3-甲基-3,4-二氮杂双环[4.1.0]庚烷-2,5-二酮 在
吡啶 作用下,
生成 (3S,4R)-3-hydroxy-2,2-dimethyl-4-[[(1R,6S)-4-methyl-5-oxo-3,4-diazabicyclo[4.1.0]hept-2-en-2-yl]oxy]-3,4-dihydrochromene-6-carbonitrile 、 (3S,4R)-3-hydroxy-2,2-dimethyl-4-[[(1S,6R)-4-methyl-5-oxo-3,4-diazabicyclo[4.1.0]hept-2-en-2-yl]oxy]-3,4-dihydrochromene-6-carbonitrile