rac-2-(((R)-1-((R)-5-acetyl-3,6-dihydro-2H-1,3-thiazin-2-yl)-1-carboxyethyl)carbamoyl)benzoic acid 在
(benzotriazo-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate 作用下,
以80%的产率得到acetyl-3 methyl-7 phtalimido-7 oxo-8 thia-5 aza-1 bicyclo<4.2.0>octene-2