乙酸酐 、
Toluene-4-sulfonic acid (2S,3S)-2,3-dihydroxy-3-[5-oxo-1-phenyl-4-(phenyl-hydrazono)-4,5-dihydro-1H-pyrazol-3-yl]-propyl ester 在
吡啶 作用下,
以90%的产率得到3-(1,2-di-O-acetyl-3-O-(toluenesulfonyl)-L-threo-glycerol-1-yl)-1-phenyl-pyrazoline-4,5-dione 4-(phenylhydrazone)