2-(5-Acetyl-3,6-dihydro-2H-[1,3]thiazin-2-yl)-2-methyl-malonic acid monomethyl ester 在
(benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate 作用下,
以
二氯甲烷 为溶剂,
反应 48.0h,
以46%的产率得到(6R,7S)-3-Acetyl-7-methyl-8-oxo-5-thia-1-aza-bicyclo[4.2.0]oct-2-ene-7-carboxylic acid methyl ester