3-amino-7,8-dimethoxy-2H-chromen-2-one 、
(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 在
吡啶 、
盐酸-N-乙基-Nˊ-(3-二甲氨基丙基)碳二亚胺 作用下,
以
二氯甲烷 为溶剂,
反应 120.0h,
以81%的产率得到(4aS,5R,8R,8aS)-8-(tert-butyldiphenylsilyloxy)-3-(7,8-dimethoxy-2-oxo-2H-chromen-3-ylcarbamoyl)-4a-hydroxy-4a,5,8,8a-tetrahydro-4H-benzo[e][1,2]oxazin-5-yl acetate