(4aS,5R,8R,8aS)-8-(tert-butyldiphenylsilyloxy)-4a-hydroxy-3-(hydroxymethyl)-4a,5,8,8a-tetrahydro-4H-benzo[e][1,2]oxazin-5-yl acetate 在
sodium hypochlorite 、
2,2,6,6-四甲基哌啶氧化物 、
碳酸氢钠 、 potassium bromide 作用下,
以
乙腈 为溶剂,
以96%的产率得到(4aS,5R,8R,8aS)-5-acetoxy-8-(tert-butyldiphenylsilyloxy)-4a-hydroxy-4a,5,8,8a-tetrahydro-4H-benzo[e][1,2]oxazine-3-carboxylic acid